SOUTH DAKOTA, the °Sunshine one of the north central United States located west of Minnesota and Iowa, north of Ne braska and east of Wyoming. It lies chiefly between the 97th and 104th degrees of longitude and the 43d and 46th degrees of latitude. This gives it an area of 77,615 square miles, being 360 miles wide from east to west and about 225 miles from north to south. It is the 14th State of the Union in respect to area. The word Dakota is of Indian origin and means "leagued or allied?" Geology and Topography.— South Dakota has very great extremes of altitude and a great variety of topography. Big Stone Lake, in the northeastern part, is its lowest point. This is less than 1,000 feet above sea-level (967), while in the southwestern portion of the State, known as the "Black Hills,o there are elevations which rise to over 7,000 feet. Harney Peak is given at 7,244 feet by best authorities. The surface also varies from that of level plains, which may be found in the James River Valley and along the Missouri, to high table-lands with gentle undulations, as east of the Mis souri and in smaller areas on the summit of the Coteaus. Then there is a region of nar row canons, hundreds of feet in depth, pre senting on a smaller scale the wildness and picturesqueness of the Rocky Mountains, as Elk Creek and Spearfish cafions in the Black Hills and the rugged, craggy needles of Harney Peak and vicinity. There are areas in the State where you cannot find a stone the size of an for a score of square miles and other sections where rocks and stones may be found, in great abundance— where erosion went on so continuously as to produce barren condi tions. The Bad Lands of White River are a good illustration of this formation. The sur face may be classified as follows: (1) The Black Hills: these are mountainous elevations — much eroded — dome-shaped peaks pushed up above the horizontal beds that cover the surrounding region (2) the Table Lands: these occupy the region just east of the Mis souri chiefly and were formerly called by the French °Plateau du Coteau du Missouri"; (3) river valleys, including the present flood plains and also higher terraces, such as the Missouri River, which divides the State in nearly two equal parts, the Cheyenne, White, James and Sioux River valleys; (4) Bad Lands, a limited area in southwestern portion of the State, chiefly along the White River. This area has some unique characteristics. These several divisions require further descrip tion to be appreciated. The Black Hills district has an area of about 5,000 square miles and occupies a prominent position in the south western corner of the State. Their true limits are distinctly marked by a sharp ridge of sandstone from 300 to 600 feet in height. This ridge is separated from the higher mass of hills by a valley from one to three miles in width, known as Red Valley, so named by the Indians from the brick red soil found there, From this valley one ascends gradually the outer slope of the hills proper and soon enters an altitude of 4,000 to 5,000 feet. This outer' slope presents great variety of soil formation.
It is underlaid by older sedimentary rocks cut in all directions by narrow and deep cartons. This feature applies to all the southwestern por tion of the State. From the broken interior edge of this slope (this sedimentary plateau) one descends a bluff and enters a central area, of slates-granite and quartziteg formation. These are in many places carved into high ridges and sharp peaks cut by numerous nar row and deep valleys and ravines and with thickly-set Rocky Mountain pine timber. Toward the south of this elevated plateau Harney Pcak rises to 7,244 feet above sea-level and toward the north Terry and Custer peaks attain quite an altitude and present a rugged and interesting surface.
The Table Lands correspond approximately to the early surface of the State. They slope from an altitude of about 3,500 feet along the western boundary eastward to an altitude of 2,000 feet near the northeast corner and to 1,450 feet near the southeast corner. This makes an average slope eastward of about four feet per mile along the northern boundary and less than six feet along the southern boundary. The highlands are eroded into un dulations and traces are present of higher strata which every here and there stand out as buttes and ridges. The region which best illustrates this peculiarity is the northern part of that district lying west of the Missouri River. On the east side of the river these high lands are less prominent and yet may be readily located. The Bijou Hills, Wessington Hills, Ree Hills, etc., are all of this same formation, are the Choteau Creek Hills and Turkey Ridge in the southern portion of the State. There are three very important valleys crossing the State from north to south. These are the Missouri, the James and Big Sioux. The Min nesota also touches the northern portion of the State where it has an altitude of about 1,000 feet above the sea. The James River Valley is from 60 to 70 miles wide and from 1,200 feet high at about the northern boundary line to 100 feet at the southern line. It has five im portant branches. One extends west from Aberdeen at an altitude of about 1,500 feet, another west from Scotland and the fourth southeast from Marion. The fifth is northeast from Aberdeen and connects this James Valley with the Minnesota. All of these valleys have been very much eroded by glacial movements and are less sharply defined than are the valleys west of the Missouri River. The Missouri River Valley is very narrow, usually less than, three miles in width in South Dakota. Its western tributaries are also marked by narrow cafion-like valleys. Examples of this are the Grand, the Cheyenne and White River cafions. Along all of these Western rivers may be found a similarity of formation quite unique and pre senting many features of interest to the stu dent of nature. On the extreme eastern side of the State, extending nearly the entire length of the same and forming for nearly 100 miles the eastern boundary, is the big Sioux River Valley. This embraces the best agricultural soil in the State and is not surpassed in fer tility by any State in the Union.