In 1792 William Robert Broughton of the Vancouver Expedition explored the lower Columbia River. He named the Sandy River "Baring River", but noted the existence of a large sand bank that nearly blocked the Columbia River at the mouth of the Sandy River. In 1805 and again in 1806, members of the Lewis and Clark Expedition explored the lower stretches of the Sandy River as they traveled down the Columbia to the Pacific Ocean. Mount Hood, at the river's headwaters, had erupted a few years earlier, causing loose sediment to collect at the river's mouth. On November 3, 1805, William Clark wrote: "I arrived at the entrance of a river which appeared to Scatter over a Sand bar, the bottom of which I could See quite across and did not appear to be 4 Inches deep in any part; I attempted to wade this Stream and to my astonishment found the bottom a quick Sand, and impassable ...".