consist of granites and gneisses of the archæan basal complex, parts of which have also been uncovered along the upper valley of the Minnesota River, where there are valuable granite quarries. Shore deposits and lava flows of the Huronian age outcrop as highly metamorphosed rocks in broad zones along the margins of these Archæan old lands, cutting into the latter in deep tongues and bands, some of which contain iron-bearing beds of great wealth. The broad Huronian belt extending southwestward from the Minnesota River contains the Sioux quartzites, a most beautiful and valuable building stone, and beds of metamorphosed red mud, the catlinite, or far-famed red pipestone of the Indians. The Lake Superior synclinal trough is occupied by Cambrian sandstones and limestones, and Ordovician rocks occur in the southeastern part of the State, consisting of the Saint Peter sandstone beds covered with Trenton limestone, a combination which has given rise to the bluffs along this part of the Mississippi, and to the Falls of Saint Anthony. Silurian rocks occur in the valley of the Red River and in some of the southeastern counties, and slight cretaceous deposits are found in various parts of the State. The Pleistocene ice invasion is most largely responsible for the present surface, the State lying in a sort of focus of glacial activity. It was entirely covered by ice in the Kansan and Iowan epochs, and in the Wisconsin epoch two great lines of invading ice met at the centre of the State, and flowed south in a great tongue into Iowa.
Mining. The prominence of Minnesota as a mining State is based principally on its iron deposits. The mineral is found in an almost pure state in the Vermilion and Mesabi ranges. Although the existence of iron in Minnesota was known as early as 1860, nothing was done toward exploitation before 1884. The State has occupied since 1894 the second position among the iron-producing States. In 1901 its output exceeded that of Michigan. Prior to 1892 the Vermilion Range was the only source of iron in the State. In that year operations were begun in the Mesabi Range, the output of which advanced from 29,245 tons in 1892, to 1,913,234 tons in 1894. Since 1895 the Mesabi Range has been the largest iron-producing range in the Lake Superior region (and probably the largest in the world). Its output advanced in 1901 to 9,303,541 tons, against 1,805,996 from the Vermilion Range, making the total output of the State for that year 11,100,537 tons, or 38 per cent. of that of the United States. The value of the output at the mines in that year amounted to $15,335,513. In the same year 10,790,953 tons of iron ore were shipped from the Vermilion and Mesabi ranges, chiefly from the ports of Two Harbors and Duluth. Minnesota has building-stone and slate, and produces cement on a small scale. The slate deposits are believed to be considerable, but they are not much exploited. The local clay is used chiefly for the manufacture of brick.
Agriculture. Although only a little over one-half (51.8 per cent.) of the land area is included in farms, the State has attained the first rank in the cultivation of certain crops. Every decade since 1850 has witnessed a large gain in the farm acreage, the largest being made from 1890 to 1900. The percentage of improved farm land has also constantly increased, reaching 70.3 per cent. in 1900. The land not included in farms is found mainly in the extensive forest areas of the northern part of the State. From 1891 to 1901 an annual average of about 375,000 acres of homestead lands were entered. The recent expansion of the farming area has been greatest in the Northwest. The formation of many large farms in that section tends to increase the average size of farms for the State, notwithstanding the division of farm holdings going on in the southern part of the State. In 1900 there were 365 farms containing each 1000 acres or more. The average size in 1900 was 169.7 acres, as compared with 139.4 acres in 1870. The rent system is becoming very common, the percentage of rented farms having increased from 9.2 in 1880 to 17.3 in 1900. About four-fifths of these were rented according to the share system. It is in this region—particularly the Red River Valley—that wheat-growing has been so extensively developed. For a number of years there was little indication that the crop would attain much prominence in the State. The processes of milling then in use could obtain only an inferior quality of flour from the ‘spring wheat’ such as was raised in the State. With the introduction of modern methods, however, this difficulty was obviated and the State mills became famous for the high quality of their product. The cultivation of wheat then increased rapidly, and in 1890 the State had become first in both acreage and production. From 1890 to 1900 the increase was unprecedented, the acreage for the latter year being 94.5 per cent. greater than for the former, and constituting 58.5 per cent. of the area devoted to cereals. The per acre production is high, and the State easily holds first rank in the production of this cereal. In parts of the State the sowing and harvesting of wheat are done with the large type of machinery which performs a number of processes. Oats has about a third as great an acreage as wheat, and ranks next to it in importance. It has always been a prominent crop in the State, and continues to increase in acreage. Owing principally to the shortness of the season, corn has never been a favorite crop, and in this respect the State stands in striking contrast with Iowa and most of the other Mississippi Valley States. Both corn and oats are grown most extensively in the southwestern part of the State. In barley and flaxseed raising also, the State takes a high rank, and increasing quantities of rye are produced. Hay and forage crops cover about one-half as great an acreage as is devoted to wheat. Of this, 69.6 per cent. (1900) consisted of wild, salt, and prairie grasses. Large quantities of Irish potatoes are raised, and the cultivation of the sugar beet has been introduced. Fruit culture is mainly confined to the southern part of the State and is not yet extensively developed.
The little attention given to the raising of corn is largely responsible for the poor showing of the State in the raising of stock. Most of the Mississippi Valley States far excel Minnesota in this respect. Nevertheless, every decade since 1850 shows an increase for all varieties of farm animals, except sheep, and mules, and asses, for the decade 1890-1900. The relative gain in the number of dairy cows was greatly excelled by the increase in the dairy produce. Of a total value of $16,623,460 for the year 1900, 66.9 per cent. represented the amount derived from sales. The
