Clarendon was established by a Methodist minister, L.H. Carhart, in 1878 as a "sobriety settlement" in contrast to the typical boom towns of that era. It earned the sobriquet "Saints Roost" by local cowboys. Other locals call Clarendon home of "trailblazers, cattle barons, cowboys, preachers, teachers, sodbusters, merchants, craftsmen, artists, old bones, and old fossils and maybe a few saints!"
In the seat of Donley County, many museums have fossilized specimens found near here from the Clarendonian Age, dating back 11 million years to the Early Pliocene Age. Today farming and ranching still remain the primary economy of the county.