BIG STONE AND LAC QUI PARLE COUNTIES. 621 



Terminal moraines. J 



The Coteau des Prairies, rising a thousand feet above Big Stone lake and the Minnesota 

 river, is conspicuously seen in the view westward from these counties; and the base of its eastern 

 slope, composed of smooth till, below the knolly and stony, rough belt of the second moraine, 

 reaches into Manfred, the most southwest township of Lac qui Parle county. 



Antelope valley and moraine. Bordering the foot of the Coteau is a tract of smooth till, 

 known as the Antelope valley, three to six miles wide, and reaching in a north-northwest course 

 across Yellow Medicine county, southwestern Lac qui Parle county, and onward in Dakota to 

 the south bend of the Sheyenne river. In Lac qui Parle county it includes the west part of 

 Freeland, eastern Manfred, the greater part of Mehuriu, and the west side of Augusta. North- 

 westward in Dakota the north branch of AVhetstone river and the south and north forks of the 

 Minnesota river lie in this depression. Its valley-like appearance is due to its situation between 

 the massive Coteau des Prairies on the west and the third terminal moraine on the east. The 

 smoothly undulating belt which thus somewhat resembles a valley and is so called, gradually 

 rises 10 or 20 feet per mile westward. Beyond a distance of a few miles this scarcely perceptible 

 ascent is changed to the steeper slope of the Coteau, on which the smooth surface soon gives 

 place to the hillocks and small, short ridges, of the second or Gary moraine. The Antelope valley 

 is virtually the continuation of the smoothly undulating or rolling expanse of till which reaches 

 with slight ascent from the Minnesota river westward across Lac qui Parle county to the third 

 or Antelope moraine. 



This third series of terminal deposits of the last ice-sheet, like the two farther west on the 

 Coteau, consists of hills and knolls and small ridges of till, containing many boulders, chiefly of 

 gneiss, schists, granite and syenite, with a small proportion of limestone. It has been traced in 

 a north-northwest course across Yellow Medicine and Lac qui Parle counties, a distance of about 

 forty miles, in this state, and it continues with the same course in Dakota. Its width varies 

 from one mile, or less, to two or three miles, and the hight of its elevations is usually from 40 to 

 100 feet above the contiguous east side of the Antelope valley. In southern Lac qui Parle county 

 this moraine forms the two conspicuous clusters of the Antelope hills, in sections 27 and 16, Free- 

 land, which rise about 100 feet above the smoothly undulating till of their region, and afford "a 

 magnificent view of the prairies on all sides and of the Coteau toward the west." Continuing 

 northward, it runs from section 32, GarfieJd, in a nearly straight course to section 33, T. 119, R. 

 4<i. One of its hills, about 60 feet high, at the north side of the west branch of Lac qui Parle 

 river, in section 18, Garfield, has been named mount Wickham. It is also sometimes called An- 

 telope mound. Thence for five miles northerly, in the northeast part of Mehurin and southeast- 

 ern Augusta, this stony belt, 10 to 40 feet above the general level on each side, is known as the 

 Stony ridge. In the east edge of Dakota, these accumulations rise prominently in the frac- 

 tional T. 12O, K. 47, and are called Yellow Bank hills, from the river of this name which flows 

 through them. Mount Tom, their highest point, in or near the N. E. J of section 32 of this 

 township, has an elevation of about 100 feet. A belt of rolling till, about three miles wide, higher 

 than the more gently undulating areas on each side, continues from these hills northwesterly 

 across Grant county and into the Sisseton and Wahpeton reservation, lying two to six miles 

 southwest of Big Stone lake, and crossed a few miles west of Brown's Valley by the road to the 

 Sisseton Agency. 



The fourth or Kiester moraine seems to be represented in T. 119, R. 46, by a series of 

 knolly drift deposits, composed of till with plentiful boulders, which extends from the northwest 

 corner of this township five miles southeastward to the elbow of the South fork of Yellow Bank 

 river. A width of only one mile separates the third and fourth moraines at the state line, but 

 they diverge to a distance of three miles apart at the South fork. The farther course of the 

 fourth moraine south-southeast to Omro and Tyro in Yellow Medicine county (page 606) has not 

 been traced, but this formation was observed in 1873 by Prof. Winchell in the south part of Lac 

 qui Parle county, probably near the middle of Providence township. After describing the Ante- 

 lope hills, he adds that "a similar range of drift knolls, but much smaller, was seen about six 

 miles east of this range, running also in the direction N. and S."* 



Later moraines. During the stages in the recession of the Minnesota lobe of the last ice- 

 sheet when its fifth, sixth and seventh (or Elysian, Waconia and Dovre) moraines were formed, 



*Second annual report, pages 193-4. 



