172 THE GLACIAL LAKE AGASSIZ. 



and the moraiuic portions ; and the latter, to which the name Big Butte is 

 commonly limited, rises to 1,750 and 1,800 feet, or 250 to 300 feet above 

 its base, the culminating point being- near its west end. This Cretaceous 

 highland, veneered with two diverse phases of the glacial drift, is situated 

 8 to 18 miles northwest of the west end of De\dls Lake. Il appears to be 

 allied geographically and geologically with the highest of the hills south 

 of De'sals and Stump lakes ; and the northwestward continuation of the 

 old valley now filled by those lakes is probably represented along a dis- 

 tance of 30 miles north and north-northwest of the Big Butte by Ibsen, 

 Hun-icane, Grass, Island, and Long lakes. 



Beyond the Big Butte this moraiuic belt is well developed in knolls 

 and hills occupying a width of several miles, only moderately elevated 

 above the general level, tlii-ough township 155, range 70, and about Horse 

 Shoe and Broken Bone lakes (the latter named from buffalo bones broken 

 for extracting the marrow in making pemmican), in township 156, range 71. 

 Next to the north of Limekiln and Broken Bone lakes and of Pleasant 

 Lake station and Rugby Junction, on the Great Northern Railway, an 

 extensive area is covered by moraiuic hills, with abundant Ijowlders, rising 

 50 to 100 feet or more above the intervening hollows and 100 to 150 

 feet above the smoothly undulating- surface east, north, and west. This 

 moraiuic area, probably representing the combined Fergus Falls, Leaf 

 Hills, and Itasca moraines, extends about 15 miles north from the railway 

 to Island Lake and Ox Creek, and an equal or somewhat greater distance 

 from east to west across ranges 71, 72, and the east half of 73, pressing 

 close to the Bottineau branch railway in the northeast part of township 

 157, range 73, and terminating thence along a south-to-north line which 

 was also the east shore of the glacial Lake Souris, passing about 4 miles 

 east of Round Lake and Barton. North of this remarkable development 

 of the moraines a smoothly undulating or only moderately rolling sur- 

 face of intermorainic till, with few bowlders, stretches from Island Lake 

 and Ox Creek across the next 15 miles to the southern base of Turtle 

 Mountain. 



Gravel, sand, and silt, dejDosited in Lake Souris, extend from Dunseith 

 southwest to Willow Cit}^ and the Souris River, excepting a belt of moder- 



