Arkansas City pronounced Ar-kan'-sas, three miles north of the Oklahoma border at the confluence of the Walnut and Arkansas Rivers, is a shipping and refining center for oil fields at the north, east, and south. Long lines of tank cars emerge from the city on its four railroads; freight yards are piled high with incoming shipments of oil machinery and pipeline supplies. The local oil refinery has a daily capacity of 20,000 barrels.