The expedition the cave is named after never set foot in it. Lewis and Clark camped along Antelope Creek on 31 July 1805, within sight of the hillside, and walked on none the wiser. The limestone caverns underneath were found in 1892 by two local ranchers, Tom Williams and Bert Pannel, who were out hunting and saw steam rising from the mountainside on a cold day, which is what a warm cave does in a Montana winter. Williams did not get around to properly exploring it until 1898.
What followed is a very American piece of history. Dan Morrison developed the cave for tours around 1900, calling it Limespur Cave, and filed a mineral claim on the land in 1905. The Northern Pacific Railroad disputed the claim, took him to court, won, and handed the land to the federal government. President Taft declared it Lewis and Clark Cavern National Monument in 1911. Montana took it over in 1937, and it became the state's first state park.
The park now covers about 3,000 acres above the Jefferson River valley, with two visitor centres, ten miles of trail and a campground, and the caverns historic district was added to the National Register of Historic Places in 2018. The cave itself is a decorated limestone system, worked by water into stalactites, stalagmites, columns and helictites, and it holds a constant temperature around 50 degrees Fahrenheit.
The standard tour is not a stroll. It runs about two hours, covers roughly two miles including the walk up to the entrance, and involves some six hundred stairs and a few places where you go down a slide worn smooth by decades of visitors doing the same. Tours are guided and seasonal, generally May through September, and the park runs candlelight tours in December that fill up quickly.
Other places on the map within a couple of hours.
