Wallula's history spans immense Ice Age floods, long Native occupation, exploration, trade, transportation, and repeated town relocations. Between 15,000 and 18,000 years ago, floodwaters from Glacial Lake Missoula surged through Wallula Gap at speeds of up to 60 miles per hour, creating channeled scablands, sending water up nearby valleys, and carrying icebergs that deposited exotic rocks at Wallula. Wallula later became a permanent village site for Wallulapum Indians and a gathering place for Walla Wallas, Nez Perces, and others, while earlier inhabitants between about 11,000 and 8,000 years ago lived in small mobile groups before later communities became more sedentary; after about 1720, the arrival of the horse increased mobility and trade, though seasonal salmon fishing, root gathering, and hunting remained central. Lewis and Clark camped nearby in October 1805 and again in April 1806, when Chief Yellepit gave Captain Clark a white horse and Clark gave Yellepit his sword. In 1818 the North West Company built Fort Nez Percés at the mouth of the Walla Walla River, and in 1821 the Hudson's Bay Company rebuilt it as Fort Walla Walla, an important fur trade and supply center whose authority was respected by local tribes. In territorial days Wallula became a major steamship port after the first steamboat arrived in 1859, carrying livestock, wheat, settlers, and miners, and it was later transformed by railroads beginning in 1871, with multiple lines making it a regional rail center by the late nineteenth century. The first town of Wallula, established in 1860, declined after the gold rush; a second town arose with the railroads in the 1880s; and after Lake Wallula inundated both earlier town sites in 1953, the town was relocated again to higher ground.