High Plains River
A loop of the Niobrara River nourishes a narrow strip of Great Plains wetlands in the Agate Fossil Beds National Monument, an oasis in the otherwise vast stretch of semiarid shortgrass prairie near the Wyoming line. The river arises not in the mountains but with (mostly) dry washes in Wyoming, near Lusk. All of its water comes from the plains themselves, mainly snowmelt and groundwater, but with an occasional, localized boost from thunderstorms. About a hundred miles farther downstream, after a trek through much of the Nebraska Sandhills and their high water table, the same river gains a good deal more size, volume and cutting power.
20 SSE Harrison NE (22 May 10) looking NW