and traded there. When the Lewis and Clark Expedition passed through the area in 1805, the explorers found a "great emporium...where all the neighboring nations assemble," and a population density unlike anything they had seen on their journey. Accordingly, historians have likened the Celilo area to the "Wall Street of the West." The Wishram people lived on the north bank, while the Wasco lived on the south bank, with the most intense bargaining occurring at the Wishram village of Nix-luidix. Charles Wilkes reported finding three major native fishing sites on the lower Columbia — Celilo Falls, the Big Dalles, and Cascades Rapids, with the Big Dalles being the largest. Alexander Ross described it as the "great rendezvous" of native traders, as "the great emporium or mart of the Columbia." Pinnipeds such as sea lions and seals followed salmon up the Columbia as far as Celilo Falls. In 1841 George Simpson wrote "these animals ascend the Columbia in great numbers in quest of the salmon. Navigation The seasonal changes in the Columbia's flow, high in summer and low in winter, affected Celilo Falls dramatically. Lewis and Clark reached Celilo Falls in the late autumn when the water was relatively low, turning the falls into a major barrier. In contrast, when David Thompson passed Celilo Falls in July 1811, the high water obscured the falls and made his passage through the Columbia Gorge relatively easy. Modeste Demers wrote about the seasonal change in 1839: "One may be astonished to learn that these chutes, so terrible at low water, are smooth and still at very high water, which does not happen every year. Then it is that, instead of fearing them, the voyageurs hasten to approach them, to light their pipes and rest." More difficult was the Long Narrows, or Big Dalles, ten miles below Celilo Falls. This section of the river was impassable during high water. During the autumn low water they were passable but with unloaded boats only, and even then the passage was very dangerous. "They are never passed without dread," wrote François Blanchet in 1839. Narcissa Whitman asserted in 1836 that over one hundred "white lives" had been lost at the Dalles. In the 1840s and 1850s, American pioneers began arriving in the area, traveling down the Columbia on wooden barges loaded with wagons. Many lost their lives in the violent currents near Celilo. In the 1870s, the Army