Ellensburg, city (1990 pop. 12,361), seat of Kittitas co., central Wash., on the Yakima River; inc. 1886. It is the trade and processing center for a region in which cattle raising and diverse, irrigated farming are predominant. Central Washington Univ. is there, and an annual rodeo is held in the city. Ginkgo Petrified Forest, Wanapum Dam, and two state parks are nearby.