Chimney Rock, an Oregon Trail Landmark

Chimney Rock in western Nebraska is a narrow spire of volcanic ash and clay rising 325 feet from a conical base on the south bank of the North Platte River. It was the most consistently mentioned landmark in the journals and diaries of pioneers traveling the Oregon Trail in the 1840s and 1850s, visible from as far as 30 miles away and used as a waypoint for days of travel. After weeks of flat plains, the sight of Chimney Rock signaled to travelers that they were approaching the Rocky Mountains and the hardest part of the journey.

Source: U.S. National Park Service