On July 19, 1805, Lewis wrote, "This evening we entered much the most remarkable clifts that we have yet seen. These clifts rise from the water's edge on either side perpendicularly to the height of 1200 feet. Every object here wears a dark and gloomy aspect. The towering and projecting rocks in many places seem ready to tumble on us. The river appears to have forced its way through this immence body of solid rock for the distance of 53⁄4 miles and where it makes its exit below has thrown on either side vast collumns of rocks mountains high… From the singular appearance of this place I called it the gates of the rocky mountains."
Beaver Creek to Hauser Lake is a 5.72 km trail near Helena, Montana that follows the historic route of Lewis and Clark's expedition through the Gates of the Rocky Mountains. The trail features towering 1,200-foot limestone cliffs rising directly from the water's edge, offering dramatic views of the Missouri River and the historic passageway that Lewis himself described as wearing "a dark and gloomy aspect."