Beavers transformed the creeks and rivers of the Great Plains into relatively lush riparian zones. This photo is from Harper’s Weekly in 1867. It shows a section of the Pawnee River about 30 miles west of Ft. Larned. You can see all trees and other plants. 2/?

Compare that image to this screen shot from Google Maps in the same approximate location and you can see the changes. Even accounting for a different perspective and season the modern river is drier. I’m betting erosion toke a toll on the banks also. 3/?