Keystone is an unincorporated community and census-designated place in central Keith County, Nebraska, United States. It lies along local roads near the North Platte River, northeast of the city of Ogallala, the county seat of Keith County. Its elevation is 3,100feet (945m). Although Keystone is unincorporated, it has a post office, with the ZIP code of 69144.

Can we draw the following conclusion?
There is only one river near Keystone
It's impossible to say