SALT FORK OF THE RED RIVER. The Salt Fork of the Red River rises near the Carson county line in northeastern Armstrong County (at 35°09' N, 101°21' W) and flows southeast across central Donley and Collingsworth counties. When it crosses the 100th meridian at the eastern boundary of Collingsworth County, it enters Oklahoma and flows east across north central Harmon and southern Greer counties. Southeast of Mangum it turns south and crosses central Jackson County to its mouth on the Prairie Dog Town Fork of the Red River, opposite the northernmost point of Wilbarger County, Texas, sixteen miles northwest of Vernon (at 34°27' N, 99°21' W). The Salt Fork and its Panhandle tributaries were the scene of military activity during the Red River War in 1874. Several early ranches, including the Half Circle K, the RO, the Spade, and the Rocking Chair, owned land on or near the stream. Clarendon was established on the Salt Fork in 1878 but moved five miles south to the Fort Worth and Denver Railway nine years later; now the original site in Donley County is partially inundated by Greenbelt Lake, with the community of Howardwick on its north shore.