Medicine Rocks State Park was once a sea of sand dunes. About 61 million years ago during the Tertiary Era, a large freshwater river deposited fine-grained sands along its shores. From there, coastal winds blew the sand into dunes that eventually compacted into soft sandstone. That soft rock was especially susceptible to wind erosion, which caused hollowed out holes in the face of the rock. The Medicine Rocks exhibit crossbedding, where thin layers of sandstone lie at angles within thick sandstone beds. For millions of years, the wind has sculpted the soft sandstone into many strange and bizarre shapes that, like shifting clouds, almost overwhelm the imagination in their complexity and ability to inspire wonder. Native Americans early recognized the distinctiveness of the Medicine Rocks. They used the area as a vision quest site, meeting place, shelter, and as a lookout to spot enemies and bison. A Lakota named Charging Bear called the rocks a place “where the spirits stayed and medicine men played.” Like the Native Americans before them, non-Indian settlers also recognized the uniqueness of the Medicine Rocks as a place to gather and enjoy one of Montana’s geologic wonders.
Slide toward Today to fade the historical sheet and see the modern map underneath.