Medicine Rocks State Park in eastern Montana preserves more than one hundred sandstone pillars, towers, and arches shaped over millions of years from deposits laid down about 61 million years ago. Fossils and archaeological evidence make it significant not only geologically but also culturally: people have lived at or near the site for about 11,000 years, many Plains tribes revered it as a sacred place, and Native American rock art remains there. Later it became part of a ranching landscape and then a public park. Known for its solitude and unusual beauty, it was added to the National Register of Historic Places in 2017 and designated an International Dark Sky Sanctuary in 2020.