Pecos (pāˈkəs) [key], city (1990 pop. 12,069), seat of Reeves co., W Tex., on the Pecos River; inc. 1903. It is a railroad and highway junction and the market for an extensive ranch and irrigated farm area; water is supplied by the Red Bluff Dam on the Pecos. It is also a sand and gravel and gas and oil center. There are cattle feed lots. The annual rodeo, held there since 1883, was the world's first.