CAMPBELL BEACHES IN NOETH DAKOTA. 415 



plateau-like mass of the Sheyenne delta, having been sculptured by wave 

 erosion during these stages of the glacial lake. The same shore-lines con- 

 tinue near together along this frontal slope through a distance of 30 miles 

 to the north and northwest, passing about 3 miles west of Barrett, 1 to 2 

 miles west of Colfax, a similar distance southwest of Walcott, about 3 miles 

 southwest of Kindred, and 1 to 1.^ miles north of Leonard. In many 

 places, however, the eroded surface as it was shaped by the lake waves has 

 been much changed since by the winds, which have heaped up its sand in 

 dunes 10 to 30 feet high. 



Beyond the northern limit of the Sheyenne delta, near Leonard, the 

 border of the lacustrine area rises somewhat steeply from the Red River 

 Valley plain, and the lower and best-defined Campbell shore-lines are 

 mostly united or lie close together, whether marked by beaches or by an 

 ei'oded escarpment. This very finely developed margin of the old glacial 

 lake has been mapped, with determination of its height by leveling, through 

 all the distance from Leonard to the international boundary, about 175 

 miles. 



The Fargo and Southwestern Railroad crosses the Campbell shore 

 close below the Tintah beaches and slightly more than a mile northeast of 

 Leonard, but it is not distinctly marked there, lying near the foot of the 

 northeastwardly declining slope of the Sheyenne delta. Its course is thence 

 west-northwest about 8 miles, crossing the Maple River, to the southeast 

 part of section 29, Walburg, where it turns to the north and holds mainly 

 a north-northeast course through the next 25 miles to Wheatland and 

 Arthur. About a quarter of a mile south of the Maple River the Camp- 

 bell shore is marked by an exceptionally massive beach ridge which passes 

 through a cemetery in the north part of section 3, Watson, its crest in the 

 cemetery and close westward being 1,008 to 1,013 feet above the sea and 

 some 75 feet above the river. This ridge consists of sand and fine gravel, 

 largely derived from Cretaceous shales, with no pebbles exceeding 2 inches 

 in diametei'. North of the narrow valley cut by this river the beach ridge 

 continues with an elevation of 1,006 to 1,009 feet for nearly 2 miles to its 

 northward bend, beyond which the shore along its next 2 or 3 miles, having 

 left the thinned margin of the delta sand brought into Lake Agassiz by the 



