“Mountains ‘as steep as the roof of a house,’ one of the [Lewis and Clark expedition's] men wrote of the Bitterroots. Buttressing the boundary between present-day Montana and Idaho, they created an unexpected, 300-mile-long [483-kilometer-long] barrier that rose to heights of 11,000 feet [3,353 meters] and more. Spotting the Rockies from Lemhi Pass, [Capt. Meriwether] Lewis was nonplussed but stoic. ‘I discovered immence ranges of high mountains still to the West of us,’ he recorded, ‘with their tops partially covered with snow.’”
—From the National Geographic book Lewis & Clark: Voyage of Discovery, 1998
