NORTH DAKOTA STATE UNIVERSITY - FARGO, N D
RED RIVER VALLEY,
NORTH DAKOTA & MINNESOTA
This image was produced from a LANDSAT satellite pass over the Red River Valley on May 12, 1975. Water reflects as black, grassland as red, and forest as brown. The prairie-forest transition is apparent as the margins of the brownish patch at the right-center of the image.
The dark gray swath through the central portion of the image represents the Red River Valley. The Valley was once the floor of glacial Lake Agassiz. The dark grays reflect "black" (like water) due to the saturation of smectitic clays in cultivated fields. The eastern margin of the Lake Agassiz basin shows as a remarkable compression of shoreline features against high glacial uplands. The western shoreline is obscure, appearing as a series of parallel ridges associated with various levels of the former lake. The fan or "delta," deposited by the Sheyenne River as it fed sediments into Lake Agassiz, appears today as the Sand Hills of Richland and Ransom County, North Dakota.