Commerce City (1990 pop. 16,466), Adams co., N central Colo., suburb, 7 mi/11.3 km NE of downtown Denver, on South Platte R.; 39°52'N 104°52'W. Elev. 5,150 ft/1,570 m. Mfg. (construction materials, flour, gasoline and petroleum refining, consumer goods, steel). Rocky Mt. Arsenal to E; state fish hatchery to N.