MINNESOTA: A STATE GUIDE
The northern boundary, for the greater part of its length, is formed by the watercourse of the Rainy River with its historic portages and interspersed lakes; the Red River along the North Dakota border forms two-thirds of the western boundary; South Dakota bounds the lower third eastern Minnesota is separated from Wisconsin by the St. Croix and the Mississippi Rivers. The center of the State is crossed from west to east by the slow-flowing Minnesota in a tremendous valley remnant of the old glacial River Warren. At the Twin Cities it meets the glacier-shunted Mississippi, whose upper course from its headwaters in Itasca Park wanders over much of the upper middle of the State to be joined finally by the broad St. Croix.
In spite of the fact that most of its boundaries follow watercourses, Minnesota's shape is fairly rectangular; it is 406 miles long from north to south, and although 357 miles from east to west along the northern border its average width is only 240 miles. Within its area of 84,682 square miles originate three great river systems: the Red River, which flows north to the Hudson Bay; the Minnesota and St. Croix, which join the Mississippi and flow to the Gulf of Mexico; the St. Louis and other North Shore streams that find their way to the Gulf of St. Lawrence through the Great Lakes.
Although water flows away from the State in all directions, the altitude is relatively low, reaching an extreme slightly above 2,000 feet only in the occasional hills of the rocky ridges north of Lake Superior. The Red River leaves the State at an elevation of 750 feet, the Mississippi has a fall of 620 feet between Minnesota and the Gulf, Lake Superior lies only 602 feet above sea level.
The surface of the State presents a great variety of topographic features. To the upper west are the flat prairies, merging into the rolling hills and valleys of the forest and lake region which attain, in the upper northeast, the semblance of mountain ridges; in the southeast the closed valleys and lakes are replaced by the unglaciated hills and deep cuts made by swift-flowing streams.
The types of hills are many and varied. There are hills formed by running water, others have been left by glacial deposit; some were made by an irresistible shove of the glacial ice; others, whose outlines are constantly changing, have been piled up by the persistent sand-moving power of the wind; while earth movements or volcanic expulsions have forced up the rougher elevations.
The floral covering of these hills varies greatly from southwest to northeast. Most of the western area, with the exception of the narrow, wooded margin along the Red River, is a treeless prairie, sometimes flat, often rolling, with acres of grain displacing the original prairie grass. This broad sweep is separated from the great coniferous forest of the upper east by a wide belt of deciduous hardwoods known to early explorers as the "Big Woods."
Minnesota's temperature is likewise varied. Lacking the tempering effect of ocean bodies it is subject to great fluctuations. The State lies in the path of the low-pressure areas that move across the continent from west to east at an average speed of 600 miles in 24 hours. The average frequency of these cyclonic air movements is twice a week. They are characterized by fair weather and warm temperatures followed by periods of rainy and cooler weather. The average annual temperature is about 40 degrees. The winters are severe and reach extremes far below zero. The summers are characterized by rapid changes and occasional intense heat waves.
Temperatures in many counties range from 40 degrees below zero to 100 degrees F. Frost, although rare from the last half of May to the first half of September, has been recorded for every month of the year. The longest growing season, 160 days, occurs in the region between the Twin Cities and Winona; in the north it is considerably shorter, in some places less than 90 days. Near Lake Superior the temperature is influenced in all seasons by the lake, but is consistently cooler than in the Twin Cities area. The prevailing winds are northwest for most of the State
The average relative humidity at 7 a.m. is 83 percent; at 7 p.m. it is 72 percent. The largest number of rainy days (132) in one year was recorded at Duluth; Lyon County has had as few as 64. The sunshine averages between 43 and 53 percent. The long hours of summer daylight in the northern counties help to compensate for the short growing season.
So long ago as to make the ice sheets that gave the State its present character seem modern, what is now Minnesota was a series of barren uneven bulges in the ancient granitic foundation of the earth. Some of this oldest known rock is still exposed. One of the most familiar exposures is Jasper Peak near Soudan and Ely in northern Minnesota. In many places it is buried under hundreds of feet of more recent rock and soil.
At noon (by the geologic clock), in the beginning of this troubled history, Minnesota was torn by great volcanic flows. The fierce lava broke through the surface to cover the land and replace seas where sediments had been slowly accumulating. (It was in these early Archean waters that the ore of the Vermilion Range was deposited.)
Some 3 hours later according to the clock--much more than a hundred million years in actual time--the earth bulged and thrust up a mountain range reaching from southwestern Minnesota northeast into Canada and on into the region of Quebec.
For an hour or more the slow process of erosion wore down the mountains, exposing knobs of harder granite and gneiss that had not been able to reach the surface. In the Minnesota Valley near Ortonville and Big Stone City, and near Saganaga Lake in the extreme northeastern part of the State, these can still be seen. (The green schists of St. Louis and Itasca Counties are lava flows changed by the mountain-building processes.)
By late afternoon, on this same shrunken scale, another mountain range was formed, extending north from the Mesabi to Canada. (Outcrops of these stones are apparent north of the Giants Range.) Upon these old lavas, granites, and altered sediments, the present surface of the State has been laid.
Still later the seas had invaded north-central Minnesota. In their sediments the valuable Mesabi formations were deposited; probably the quartzite, with its now famous pipestone or catlinite deposit, formed at this period also. Volcanic masses again broke through cracks to cover much of the northeastern area and to spread as far as the Mesabi Range and Taylors Falls. Their remains are still plainly visible along the North Shore of Lake Superior. Close upon this vulcanism came a tremendous movement that folded the surface and made the dip that was destined to be the bed of Lake Superior.
By this time the formations had become so jumbled that scientists who sought to differentiate them were forced to devote years of research to their study. The most intensely studied region of the State comprises the iron ranges. It has been said that if iron were as precious as gold and silver, every farm in Minnesota would be a mine; but iron is one of the most common elements of the entire earth, and is found not only in rocks, but in most living things.
Many common minerals that appear insoluble are in time dissolved. Some of the richest iron ore is the residue after a gradual removal by solution of silica and other minerals. Again, water laden with dissolved iron has seeped through iron-bearing rocks and given up its metal. In a great many places throughout the State are to be found scattered residuary and enriched iron deposits, rich enough for smelting, but as a rule too small to warrant mining and shipping.
In the area known as the Lake Superior Region, covering much of upper Minnesota, Wisconsin, and Michigan, occur large concentrated deposits of Some of the richest iron ore found anywhere on the earth. These concentrations appear in geological folds of rock known as the iron ranges. Not in any sense mountains, these ranges are rather the roots of very ancient and tremendous ridges worn down and now almost covered by the tons of drift or soil brought by the glaciers. Part of this rocky mass is exposed as far west as the Minnesota River valley and it extends far beyond the borders of the State.
Even though several of these rock masses are called iron ranges they are not uniformly ore bearing, but rather punctuated with pockets and sheets of iron ore. The total area of the ore-bearing soil is but a fraction of the entire formation. In the ancient rocks of the Vermilion Range the ores which are of the hard type, are found in deep-pitched troughs so complex that in spite of extensive exploration it is not certain that all of the pockets have been found. This Vermilion district is from 5 to 10 miles broad and 100 miles long; the highest spots, which rise not more than a few hundred feet above the surface, are usually oblong in outline. The valleys and lakes also are attenuated in the northeast-southwest direction.
Mesabi, variously spelled, is from the Indian word for giant. In this range, as in the older Vermilion area, is a slight ridge merging on the southwest with the level country, but rising roughly a few hundred feet at its eastern end. It too lies in the general northeast-southwest direction but its south slope is quite abrupt. The length of the ridge is about 110 miles, the width from 2 to 10 miles. Along its foothills are the ore deposits, usually of the soft variety, lying in broad stretches, more horizontal than in the Vermilion Range.
The Cuyuna Range differs from the other two in that it has no surface ridge or mark, but is entirely covered with glacial drift whose depth varies from 80 to 350 feet. The discovery of iron here was made by means of the dip needle. The ore consists of both the hard and soft varieties.
"The iron-bearing formations of the Lake Superior region consist essentially of interbanded layers, in widely varying proportions, of iron oxide, silica, and combinations of the two, variously called jasper or jaspilite. These rocks become ore by local enrichment, largely by the leaching out of silica and to a less extent by the introduction of oxide. There are accordingly complete gradations between them and iron ores. Many of the intermediate phases are mined as lean siliceous ores."
Returning to the story of geologic time--Minnesota's evening was a quiet one, far removed from the mountain-making thrusts. The hills wore away to fill the sea; a great arm from the Atlantic reached the southern part of the State and the sediments formed the sandstone, limestone, and shale observable in the river ledges from Taylors Falls to Iowa. The receding sea left the sediment exposed to erosive processes, returned again, and once more receded. Sometime within the next few hours by the clock, while land animals were developing and reptiles were being displaced by smaller, more highly developed forms, the sea made its final thrust in the direction of Minnesota, this time from the Pacific. Thwarted by the Rockies this effort was of brief duration, and marked the end of the State's marine history.
During the few seconds preceding the era of recent time, occurred the activity that has given the landscape its familiar characteristics. From out of Canada came the ice to cover much of the continent and all of Minnesota except its small southeast triangle. During those thousands of years, only the few final seconds on-the clock, the ice made four incursions and retreats. Down the valleys moved this huge load, slowly but irresistibly scouring rock ridges, polishing knolls, breaking off and shoving boulders about, unloading tons of soil, and, as it finally melted, leaving heaped-up debris in the form of innumerable moraines to dam up ten thousand lakes.
The earliest of the invasions, sometimes called the Nebraskan, covered almost the entire State and left a gray layer of soil or drift. After an iceless interval this invasion was followed by another less extensive, and this too deposited a gray covering of soil. Then came the Illinois tongue entering from the East. (Its remnant is a bright red layer of soil, in some places covered only by its own weathered topsoil, in others protected by subsequent drift.) The final invasion came in three lobes: the Keewatin tongue came down from the northwest along the Red River and Minnesota Valley to Iowa and thrust broad lobes eastward; the Labrador pushed through the Lake Superior basin westward to deposit its load of pinkish drift; the Patrician, from the north of Lake Superior, brought a gray or lavender film but picked up on the Iron Range a mixture of iron rust which was scattered to its southern tip below the Twin Cities. This middle lobe came a bit earlier than its eastern and western collaborators and had receded before they deposited their own distinctive soil.
To these glaciers Minnesota owes its fertile pulverized limestone that has made wheat raising lucrative, and to them also it owes its undulating surface, its thousands of shallow water-filled depressions, its gravel beds, and, less fortunately, its boulder-strewn fields.
The retreating ice left the huge Lake Agassiz. Until the ice barring the northern Red River exit had melted away, this great body of water, larger than the combined Great Lakes, occupied the northwestern part of the State and extended well into the Dakotas and Canada, draining southward through the huge River Warren, in whose bed the Minnesota now flows.
Lake Superior is a remnant of the much larger and higher Lake Duluth Barred by the melting glacier from draining through the present Great Lakes channel, Lake Duluth forced an outlet southward and sent its waters coursing down an ancient St. Croix.
To one who has never seen a fossil or cracked open a stone to find within it the perfect outline of a strange crustacean or a familiar shell such a search may seem complicated by technicalities. Most fossil layers in Minnesota are deeply buried, but their edges are often sufficiently exposed for examination along the rivers and streams in the southern part of the State. Many of the fossils found, as well as those collected from other States and foreign countries, are on display with accompanying explanations in museums in the Twin Cities and elsewhere.
Although scientists agree that plants and animals must have appeared in the long ages before the period known as the Cambrian, such forms have only rarely been preserved. But in the later cycles of Minnesota's geological history, when the seas submerged much of the midcontinent, myriads of mollusk-like animals--trilobites similar to the crustaceans of today and other forerunners of modern ocean life--lived, died, and were preserved in the rock layers that underlie the soil. The gray shales and sandstones of the earliest and thus deepest of the fossil layers--the Dresbach--contain several kinds of trilobites, shelled brachiopods, strange forms called pteropods, and cystoids, together with numerous trails and borings of worms. This layer can be seen today at Taylors Falls and along the Mississippi River near Winona. Immediately above it, and in many cases undifferentiated from it, is the Franconia, visible near the town of the same name along the St. Croix. A later Cambrian deposit, the oldest of the State's limestone layers, is the St. Lawrence, exposed at a former village in Scott County for which it was named. These hard layers are spotted with the stony remains of ocean forms. Nearer the surface, although in most places far beneath the topsoil, is a thick layer of Jordan sandstone, named also for a town in Scott County where the layer is uncovered in the quarry beds. This layer can be seen in many places but is especially well exposed along the St. Croix at Stillwater. Here, at Boom Hollow, is a highly fossilized stretch, although as a rule this layer is a poor fossil carrier.
Between the Cambrian period, whose separate layers are often more than 150 feet thick, and the succeeding layers of the Ordovician period, there is no sharply defined distinction, although the sea is believed to have receded and returned again. Where the waters were quiet and deep, the lime-carbonate shells of the myriads of marine animals were gradually changed to the familiar limestone, through the slow filtering of sea water followed by centuries of drying and pressure. The interlarding of these lime layers with sandstone is evidence of the changing levels and character of the seas.
The deepest of the Ordovician layers is the Oneota, observable from Garden City north to Chaska, from the river level at Hastings to the bluff top at Red Wing, and from there southward where it forms the tops of the bluffs. Although scientists have differentiated this layer from the preceding ones, the uninitiated will find them very similar. But new animals constantly appear and others, rare in the older rocks, here become more numerous. Cephalopods (related to the nautilus), gastropods, and trilobites were common and widely varied. The New Richmond sandstone and the Shakopee dolomite intervene between the Oneota and the next layer, the St. Peter, in whose porous structure the fossils are more difficult to find. It is in the St. Peter sandstone that numerous sewer and cable channels, mushroom and cheese caves have been cut. Carver's Cave and many less well known but much more extensive natural caverns also occur in this layer.
In the succeeding muddy depositions countless microscopic animals were buried, among them marine worms, primitive fish, and chaetopods (worms with bristle-like legs). The deepening seas then deposited the shales of the Glenwood beds, which are often erroneously called soapstone.
The succeeding limestone beds of the Platteville period (exposed along the Mississippi between the Robert Street Bridge and St. Anthony Falls) contain millions of sea-living animals, corals, graptolites (colonial water animals with no living representatives ), and many other successors of earlier seas. Above the Platteville is the most highly fossilized of any Minnesota stone--the Decorah shale--which is exposed in many places, notably below Cherokee Park. Scores of species of animals have been identified from a single piece of this stone. In addition to the usual forms there are new sponge-like animals--bryozoans and many others. One cephalopod fossil from this layer, now on display in the geology museum of the University of Minnesota, is more than 5 feet long, and specimens are known to have reached 15 feet. The cephalopod was truly the giant of the Ordovician period, exceeding in size any animal of its time
The Devonian seas are represented in Minnesota only in the Cedar Valley limestone which is exposed from a few miles west of Granger northward across Spring Valley into Mower County. Minnesota had become dry land while Iowa still lay at the bottom of the sea. Although the Cretaceous seas covered a good deal of Minnesota, their animal deposits are scarce they include the oyster beds of the Mesabi. Exposures along the Minnesota River valley above Mankato are, however, a rich and valuable source of plant remains. Tulip trees, magnolias, laurels, pomegranates, and even giant sequoias made a luxuriant cover over prehistoric Minnesota, and were intermixed with many trees, such as willows and poplars, typical of a temperate climate. They were replaced by primeval evergreens, the well preserved remains of which are constantly coming to light
With the receding seas the life record for Minnesota becomes obscured Land forms are much more rarely preserved. No evidence has been found that dinosaurs wandered over Minnesota as elsewhere--though doubtless they did. Huge tusks, joints, jawbones, and teeth of elephant-like animals found in the glacial drift, bones preserved in peat-bogs, plants from the deep muck of ancient swamps, all point to a strange Minnesota. But those ages during which the coal beds of the eastern States and other famous deposits were being formed, and the modern living forms evolving, have left here only scattered and incomplete traces.
Natural processes, though slow, are never ending, and the contour of the land changes constantly. In Minnesota, lakes are disappearing, the lime of rich calcareous drift is being used up rapidly in the forested area- the prairies, more exposed to erosive elements, are becoming more uniform in texture.
Once the most characteristic feature of the transition area was its heavy cover of hardwoods, a not inconsiderable part of the timber that covered more than 7o percent of the State. A part of this hardwood belt, in regions where the soil was rich with lime and the rainfall sufficient, became known very early as the "Big Woods." The region so-named extended from Mankato to about 110 miles north from the Twin Cities and was in places 40 miles wide. The trees were principally sugar maple, basswood, and white elm, with some slippery elm, red and green ash, butternut, and bur oak. Beneath the undergrowth of ironwood, maple seedlings, dogwood, and other shrubs, bloomed hepaticas, anemones, bellwort, dutchmans-breeches, bloodroot, and trillium. Little of this beautiful forest remains; its trees have been cut and its undercover grazed.
Adjoining the "Big Woods" on the east and on the north, where the less fertile red drift covered the surface, the white oak thrived, and on the sand plains grew the still smaller scrub oak. In these less dense forests was an underbrush of many plants including wild roses, blackberries, and New Jersey tea. Flowers were more abundant than in the heavy forest-- rue anemone, wiid geranium, lily-of-the-valley, Canada anemone, and sweet pea in the spring; aster, goldenrod, and other plants in autumn. Here, as in the "Big Woods," man has modified the picture, leaving few of the forests in natural condition.
In many places the hardwood is invaded by both conifers and prairies. Near Anoka is a black spruce and tamarack swamp, a short distance away, an exile growth of cedar, a little farther are desert-like dunes and intermixtures of prairies. South of the Twin Cities, where the tamarack is found occasionally, it is without its most constant northern companion, the black spruce, although its smaller associates--the pitcherplant, twinflower, bunchberry, and the rare pink-and-whice ladyslipper--are able to survive the warmer weather. All of these flowers flourished forty years ago within the city limits of Minneapolis. Now, however, few of these transition swamps remain in the original condition. Most of them have been drained or their trees cut for firewood.
In the extreme southeastern tip of the State and almost isolated from the more northern belt, the hardwood forest exists in its most varied form. Mixed with the species from the north are the more characteristically southern trees such as black oak, black walnut, river birch, and Kentucky coffee. Topping a bluff at Winona are red cedar or juniper, familiar to north woodsmen. Here the white pine lives precariously, far removed from its preferred colder environment.
More highly valued by the early fortune hunters than the hardwood groves were the great coniferous forests that covered the entire northeastern third of the State and extended southward to within so miles of the Twin Cities and west almost to the Red River Valley.
This timbered expanse comprised most of Minnesota's virgin forest of 38 million acres. Of this entire area less than half remains, and only in isolated spots are there remnants of the virgin timber--white, jack, and red or Norway pine--which grew in almost pure stands on the higher areas or were intermixed with white spruce and balsam fir. White birch is the only deciduous tree to grow abundantly with the evergreens, but poplar and aspen, black and mountain ash, red maple, pin cherry, and yellow birch are scattered throughout the area. Here, where farming is not intensive, many of the swamps still exist in original form, their black spruce and tamarack often accompanied by white cedar. Since the hardwoods require a rich soil, and cannot survive late frost, they are restricted in the evergreen belt, to lake shores and protective ridges such as are found in the vicinity of Mille Lacs.
Trailing-arbutus, wintergreen, Labrador-tea, and dwarf kalmia are widespread in the forest openings. Blueberries and cranberries are sufficiently abundant to be economically valuable. Familiar shrubs are white-flowered thimbleberry, mountain maple, dwarf birch, sweetfern, elder, and several varieties of honeysuckle.
Fire and lumbering have changed the ratio of evergreen and deciduous trees. Poplar and birch spring up quickly when the evergreens are destroyed, to be replaced by conifers only after years of undisturbed growth. If the seed has been destroyed, or if burning is frequent, the plant cover of the area changes from evergreen to brush forest and finally, with the depletion of the soil, to unproductive thicket.
Since the first commercial cutting of the white pine at Franconia on the St. Croix, waste and carelessness have characterized the lumbering process Fires, greatly augmented by the neglected piles of slash, have destroyed millions of additional acres.
Not until most of the timber reserves had been invaded and many of them destroyed did Minnesotans realize how great and lasting a loss would result from their heedlessness. Many areas suitable only for forests had been sold to farmers whose lives were spent in trying to produce crops on an unproductive soil. Their consistently meager returns, poor even in the best years, left them desperate when the depression came. The problem of reallocating farmers and reforesting their farmsteads is one of the most difficult of Minnesota's conservation problems.
Early farmers cut the trees in order to plant crops, erroneously believing that the prairies were not fertile. Their supposition ultimately was disproved and the prairies now are the most intensively cultivated lands of the entire State.
From Canada to Iowa they extend, a great almost unbroken expanse covered over all but a southeastern tip by the rich glacial drift. Along the margins of the hardwoods they intrude to associate in many places with the true coniferous forest. Along this wooded border bur oaks and small trees push into the prairies where, as their struggle with arid land becomes greater, they are dwarfed into mere shrubs.
Intermixed with the prairie grasses, blossoming herbs and low shrubs flourish. In the spring, puccoons, birdsfoot violet, prairie phlox, and wild roses bloom. Blazing-stars, goldenrod, and asters flower in the autumn. These, since intensive cultivation has removed them from large areas, can be found only in isolated spots on steep hillsides and in the barren sandy stretches. Not even the forests are so quickly and permanently modified as is the virgin prairie.
The aquatic vegetation of each of the three vegetational regions is distinctive. Although the swamp trees are rare in the prairie area, the lakes are bordered by trees even in the more arid sections. Along the larger streams and bottom lands, the willows and cottonwoods grow. Far out on the prairies the species are limited, although boxelder and maple are quite sure to thrive on any of the higher river banks. Most lakes and ponds have heavy growths of aquatic and subaquatic plants. The surfaces of many shallow ponds are covered with yellow and white waterlilies, nearly all of the lakes have submerged waterweeds; bulrushes and cattails crowd along the shores. All of-these plants tend to fill the lake and finally, when a drought comes and the water level falls, another lake has been obliterated.
So gradual is this transition that only the most observant realize that it is the fate of all these lakes to disappear as have those of the older glacial-drift area of the southern part of the State. During its transition a lake may survive as a swamp filled with tamarack, or become a sedge-covered meadow, and eventually a wet prairie.
Long before its mineral wealth was dreamed of, Indians and adventurers were feasting on Minnesota's game birds, mammals, and fish, indeed no explorer could have survived without their aid. Since that day when Radisson wrote: "We killed several other beasts as Oriniacks (moose), stagg (elk), wild cows (buffalo), Carriboucks, fallow does and bucks Catts of the mountains, child of the Devill, in a word we lead a good life," Minnesotans have looked upon their game as public property. But furriers and firearms have so changed the game picture that to the hunter of today Radisson's account sounds like a fabulous dream.
After 1830 the once common buffalo came rarely and soon disappeared; the elk, too rare to be regarded as a resident, is perhaps even now extinct; the prongbuck or antelope, although at one time found in western counties, no longer inhabits the State.
The only large mammals commonly found within its borders are the white-tailed deer, the bear, and the moose. The deer, whose population in 1930 was estimated at one hundred thousand, has been forced into the northern half of the State by the extension of cultivated areas, although previously it roamed throughout the forested regions. The moose, much more exclusive than the deer, restricts its wanderings to the extreme northern border area where it is increasing in numbers. Its population in 1930 was estimated at four thousand, but since it has little regard for international boundaries, its numbers are widely fluctuant. Traditional enemy of the deer is the bear, of which one species abounds in Minnesota woods to the exasperation of campers and rangers whose food stores are never safe from its maraudings. Its food habits are, however, much less sanguinary than commonly believed, for weeds, fish, insects, acorns, and berries are important in its omnivorous diet. The Minnesota representative is the black bear, but it varies considerably in color; one familiar variation is the cinnamon bear. The grizzly, now confined to the Rocky Mountain area, once hunted along the western Minnesota boundary.
One of the last and possibly the only herd of woodland caribou to be found within the United States grazes in the border area of Upper Red Lake. This relative of the European reindeer is distinguished from the deer family by the fact that the female carries rudimentary antlers. The Minnesota herd probably does not exceed thirty or forty animals.
The cougar, known as mountain lion or panther, never common in the State, has been exterminated, but its two smaller relatives, the Canada lynx and the bay lynx, or bobcat, are present. The Canada lynx, which may attain a weight of thirty pounds, is rarely seen except in the northern woods, but the smaller bobcat occasionally appears throughout the wooded areas.
The red fox, progenitor of the valuable and often domesticated silver and black, is abundant in much of the region. Together with its highly bred captive descendants it provides the State with the largest single income from pelts. (Licensed breeders in the State keep approximately 10,000 foxes on their farms.) The more agile gray fox borders the Wisconsin boundary and is apparently extending its range, but, although a beautiful animal, it has little commercial value. Mink breeders have increased the mink population tremendously, but trappers still catch thousands of these animals each year. Next in value of the hunted furbearers are the muskrat, skunk, weasel, and raccoon.
A gnawing animal with undeniable distinction is the porcupine. Not the most attractive of the woods animals he is nevertheless friendly and deliberate. He does not, as commonly supposed, shoot his spines at an enemy; strangely enough, however, he is born with a full supply. He gleans his food from trees and roots; forest fires are his constant enemy, although his indifference to danger leaves him a victim of many other hazards.
More wary of man is the beaver, once the most lucrative to fur traders of all the western animals. Its skillfully built but conspicuous home is doomed to constant depredations in spite of stringent laws. The beaver is most frequently seen in the northern forests where the numerous lakes provide its aquatic habitat, but it is increasing in numbers, and is extending its range far into the prairie.
By far the most familiar of the entire rodent group are the gray squirrels whose two varieties are found in almost every wood. Occasional black and even white squirrels are variations from the normal color, not different species, as many believe. There are northern and southern species of red squirrels but they are not easily identified.
More restricted geographically is the large fox squirrel whose normal color is decidedly brownish. It is quickly recognized by its large rustycolored tail. Its habitat extends from the southeastern border well into the State Two flying squirrels, a northern and a smaller southern variety, live in the eastern border woods, but since both varieties are nocturnal, only the most inquisitive naturalists find them.
Many other small mammals are abundant. The ubiquitous house rat and mouse, introduced by man, are responsible for the calumny heaped upon their shy woods and prairie relatives. Most of the wild Minnesota forms are harmless, or only locally a nuisance. In addition to the common meadow mice, the observant may see the long-legged deer mouse, the rare grasshopper mouse, the tiny harvest mouse, or the queer stump-tailed bog lemming. None of these animals hibernates, unlike the incredible and more distantly related jumping mice.
Typical birds of the western prairies are the western meadowlark and Brewer's blackbird which, in the transition zone, sometime meets the ArctiC three-toed woodpecker, which ventures south as far as the Twin Cities or the eastern cardinal, once thought to be restricted to the regions south and east of the Minnesota border. Only in the western part of the State, however, can one see the lark bunting, the western burrowing owl, and other of their associates.
Occasional southern species such as the eastern mockingbird, the Carolina wren, and the Louisiana water thrush, may stray to the Twin Cities but usually are found only in the extreme south. Many inhabitants of the coniferous forests, such as the Canada spruce grouse, the Canada jay, the northern raven, and the southern pine siskin, are rare or absent in the rest of the State.
The bottom lands and the thousands of lakes and ponds afford congenial haunts for immense numbers of water birds. But the cultivation of extensive areas has caused great changes in bird life. Many species once abundant have become rare or extinct; constant hunting and the advent of the stray domestic cat have helped to reduce the avian population
The total number of species of birds known to occur regularly in Minnesota is 268. There are 22 additional subspecies and more than so rare or accidental visitors. Of the total population #18 nest regularly within the borders of the State. Of the three introduced species, the English sparrow is most obvious, the ring-necked pheasant most valued, and the starling the most frequently unrecognized.
Although migration begins in April, the bird student at the latitude of the Twin Cities usually sees the largest number of species in May. Since the flight of migratory birds often follows the great river courses, the Mississippi Valley and its branches are rich in bird visitors.
The hunting season varies from year to year as does the bag limit (see GENERAL INFORMATION, and SPORTS and RECREATION). Waterfowl, other migratory species, and the now naturalized pheasant are favorite game birds, but the State protects several species once favorites of the sportsmen.
Minnesota's lakes and streams contain abundant fish populations; nevertheless they require continual restocking to insure a constant supply. Although some of the large varieties, like the spoon-billed catfish and sturgeon, have become rare or restricted in their range, the game fish have not so suffered
Contrary to general belief the present population of brook trout is derived from imported stock. The native trout of north shore streams was cornpletely fished out before conservation measures were adopted. This popular trout now thrives in all parts of the State where the water is clear and sufficiently cool. The steelhead and rainbow trout have become naturalized and furnish good sport to the angler in the Lake Superior region. The German brown trout thrives in warmer waters. Lake trout are abundant in Lake Superior and in certain other northern lakes. Minnesota's pike-like fish, the muskellunge, the northern pike or pickerel, and walleye are usually abundant. The muskellunge is the rarest and is restricted to lakes in the region of Park Rapids and Lake of the Woods. Small-mouth, striped, and large-mouth bass are but three of the many varieties of popular game fish. (See SPORTS and RECREATION.) There are many other species of importance to commercial fishermen (see INDUSTRIAL DEVELOPMENT). Carp, unfortunately introduced about 1883, receives universal condemnation from anglers, but is used commercially to some extent.
The number of reptiles and amphibians in Minnesota is small, in comparison with more southern States. Only 17 amphibians occur here; of the salamanders only the tiger is common. The common toad is found over the entire State. Four of the nine species of frogs are diminutive tree varieties.
Of the 27 reptile species, 3 are lizards, 9 are turtles, and 15 are snakes. Only the rattler is poisonous and it is confined to the southeastern border. The timber rattler is fairly common but the smaller massasauga rattler has been found along the Mississippi in Minnesota, although occurrence records are extremely rare. All the other snakes are not only harmless, but decidedly beneficial by reason of their food habits. The only reptile of possible commercial use is the turtle, of which several species are used as food.
Within two years of its establishment the department faced a severe emergency in the drought of 1933. Its usefulness in co-ordinating drainage and erosion projects, drought relief, forest, game, and fish conservation at that critical time justified the hopes of its enthusiastic sponsors.
The problem of conservation is still, however, a portentous one. Large areas, once forested, are now tax-delinquent farmlands unfit for private use. The committee on land utilization, appointed by Governor Olson in 1932, reported (1934) that "inefficiency and incompetency, a palpable neglect of public welfare, a careless and unsympathetic conduct of the business of the State, unpardonable ignorance, and sometimes downright dishonesty are revealed in the manner that the land has been disposed of or exploited in the past."
The area with which they were most concerned, the northeastern counties, includes 37.3 percent of the total area of the State, a region larger than the State of Maine. From areas of unproductive cut-over land many farmers have eked out a precarious living. Many inhabitants have been moved to more productive lands, others continue only with public aid, unable to pay any taxes. It is in this region that the greatest conservation and rehabilitation projects of the State are being undertaken.
Several agencies are engaged in the attempt to recoup the wasted forests. The State divisions of forestry and parks have co-operated with Federal authorities in an aggressive campaign to reduce forest fires which, as recently as the years 1930 to 1935, destroyed 13,791 acres of Minnesota's timber valued at five million dollars. Ambitious reforestation projects involve replanting of many acres of forests each year. Technical advisers aid in such varied projects as silviculture, insect and plant-disease control, drainage, and park management, all of which affect the conservation of the forest lands.
The extensive peat beds that underlie many acres of soil have received relatively little consideration and many acres have been burned. Conservationists believe that in addition to their potential fuel value. they may eventually be important commercially as fertilizer.
The drought has focused attention on a wasteful, but controllable process--soil erosion--which is greatly accentuated when plant covering is lost. By far the most destructive erosion occurs in the loamy cultivated soils of the southern part of the State. Here drainage gullies form rapidly and the rolling hills are soon marred by denuded banks. Demonstration plots built by Government experts are showing farmers how to save their valuable soil; for the larger areas more extensive methods must be devised.
Inadequate investigation has prevented the maximum conservation of Minnesota's lakes. Their use for water storage, for fish propagation, recreational development, protection, and food production depends upon further careful study. The State maintains seven hatcheries with several field stations and substations. (See SPORTS and RECREATION.) A number of lakes are periodically closed to fishermen as a conservation measure. Prohibition of fishing during the spawning periods and the limitation of daily catches, help to insure a continuous fish supply. A large area in the Superior National Forest is permanently closed to hunters, but open to fishermen and canoeists. Other smaller refuges are scattered throughout the State, usually in the vicinity of large lakes or cities.
Water conservation, since it affects timber and other crops, recreation areas, and wildlife habitats, is of great importance in the State. An adequate control of water requires storage near the headwaters of the great river systems, prevention of drainage from the multitudinous lakes, and controlled drainage of the rocky region of Lake Superior whose scenic and recreational needs demand constantly flowing streams. Since Minnesota provides headwaters for the Hudson Bay, the St. Lawrence, and the Mississippi, its water conservation policy affects many other States and has even international significance.
Water power near industrial centers has been extensively developed; but in isolated regions it is still not utilized. The State's estimated undeveloped water resources total approximately 200,000 horsepower; 300,000 horsepower is now utilized (1938).
Associated with the wet lands and bogs are enormous deposits of marl or bog lime, a valuable soil replenisher which is widely distributed in the central part of the State. It occurs in layers sometimes many feet thick, is easily obtained, and, being soft and chalklike, requires little preparation. The marl deposits are supplemented by inexhaustible supplies of limestone. The latter is in layers sometimes 100 feet thick in the ledges exposed by the down-cutting of the Mississippi River. It must, however, be crushed and ground before it can be used on the land. Since the cost of transporting these minerals may be prohibitive, it is important that sources of supply be found close to the place of their use.
It is estimated that one and a quarter billion tons of merchantable ores remain in Minnesota; in addition there are more than so billion tons of poorer grades which may at some time prove usable. More than a billion tons of iron ore have been removed in a little more than fifty years, and at the present rate the richest ore supply soon will be exhausted. Conservation of this resource demands the complete extraction of ore from all mines before they are abandoned and become water-filled. With the hope of finding profitable use of the low grade ores, processing experiments are now being conducted at the State University.