360 THE GLACIAL LAKE AGASSIZ. 



is a mile farther east, at Wellington Stewart's lionse, iu the southwest quarter 

 of section 4, 1,192 feet above the sea. 



On the road from Olg-a to Walhalla the crest of the east margin of this 

 delta is crossed in the north part of section 33, Walhalla, about 2 miles 

 southeast from the village of this name. Its elevation is 1,190 to 1,196 

 feet above the sea. This is a beach accumulation, belonging to the third 

 Herman stage. Toward the west and southwest the undulating delta 

 plateau, mostly covered with bushes and occasional trees, is 10 to 30 feet 

 lower for a width of 1 to IJ miles, averaging about 1,175 feet. Northeast 

 from the crest of this road a short descent is made to a prairie ten-ace, 30 

 to 60 rods wide, varying in elevation from 1,182 to 1,169 feet, but mainly 

 within 2 feet above or below 1,175 feet. In general the verge of this 

 teri'ace is its lowest portion. Thence a very steep descent of 169 feet is 

 made on the road from 1,173 to 1,004 feet, this being the very conspicuous 

 wooded escarpment called the "first Pembina Mountain." It is the eroded 

 front of the great Pembina delta, the eastern part of which, originally 

 descending more moderately, has been swept away by the waves and shore 

 currents of the lake during its Norcross, Tintah, Campbell, and McCauley- 

 ville stages. From this section 33 the "first mountain" extends southeast 

 to sections 13 and 24, township 162, range 56, and laorthwest across the 

 Pembina, passing close southwest of Walhalla and onward to sections 10 

 and 3, township 163, range 57. Its highest part is intersected by the Pem- 

 bina River, above which it rises on each side in bluffs of gravel and sand 

 200 to 250 feet high, with their crest a half mile to 1 mile apart. From 

 this upper portion the delta slopes down gradually toward the southeast 

 and toward the northeast and north, extending only 2 to 4 miles north of 

 the Pembina.^ 



' The first Pembina Mountaiu was visited by D. D. Owen in 1848. He describes it as follows : 

 " Pembina Mountain is, iu fact, no mountain at all, nor yet a bill. It is a terrace of table-laud, the 

 ancient shore of a great body of water that once filled the whole of the Red River Valley. On its 

 summit it is (juite level and extends so for about 5 miles westward to another terrace, the summit of 

 which, I was told, is level with the great buffalo plains that stretch away towards the Missouri, the 

 hunting grounds of the Sioux and the half-breed population of Red River." — Report of a Geological 

 Survey of Wisconsin, Iowa, and Minnesota, 1852, p. 178. 



Both the first and second Pembina mountains were examined in 1857 by Palliser, who says of the 

 fiat Red River Valley and the Pembina delta: " This plain, no doubt, had formed at one time the bed 

 of a sheet of water, and the Pembina Hill, consisting of previously deposited materials, was ita 

 western shore." — Journals, detailed reports, etc., presented to Parliament, 19th May, 18G3, p. 41. 



