Lewis and Clark spotted the mountain on October 18, 1805. A few days later at what would become The Dalles, Clark wrote, "The pinnacle of the round topped mountain, which we saw a short distance below the banks of the river, is South 43-degrees West of us and about . It is at this time topped with snow. We called this the Falls Mountain, or Timm Mountain." Timm was the native name for Celilo Falls. Clark later noted that it was also Vancouver's Mount Hood.