The original people of the region were the Chemnapum Indians (closely related to the Wanapum tribe), living near the mouth of the Yakima River. Lewis and Clark passed through the area in 1805, and an expedition of the Army Corps of Topographical Engineers headed by Robert E Johnson mapped the Yakima Valley in 1841. The Yellowstone Trail, a national highway stretching from Albany, New York, to Seattle, was located through the Yakima Valley in 1917 and 1918. It crossed the Fallon Bridge between Richland and West Richland and then proceeded directly west to Kiona.