Keystone is an unincorporated community and census-designated place in central Keith County, Nebraska, United States. As of the 2010 census its population was 59.It lies along local roads near the North Platte River, 13 miles northeast of the city of Ogallala, the county seat of Keith County. Its elevation is 3,100 feet above sea level. Although Keystone is unincorporated, it has a post office, with the ZIP code of 69144.