Minnetonka is one of the larger limestone caves in Idaho, cut into the mountains of Cache National Forest above St Charles, at the northern end of Bear Lake. The half mile tour route is lined with stalactites and stalagmites, and it is run by a concessionaire under a special use permit from the Forest Service rather than by a private owner.
The name is a borrowing, and a slightly garbled one. It comes from Mni Tanka, from one of the Dakota, Lakota or Nakota dialects, meaning big or large water, which arrived here by way of Minnesota rather than from the local Shoshone country.
Two things make the visit different from a lowland show cave. The first is temperature: it sits at 40 degrees Fahrenheit all year, colder than most caves people have been in, and it does not warm up in August. The second is that you earn it. The route involves roughly 450 stairs down and the same back up, at an elevation over 7,700 feet, which catches out visitors who have driven up from sea level that morning.
The cave is a hibernaculum for five species of bat. One of them, Townsend's big eared bat, is not federally listed but is carried as a species of concern by both Idaho and the Forest Service, and restrictions are in place to keep white nose syndrome out. If you have been in another cave, do not bring the same boots, clothing or lights.
Tours open on Memorial Day weekend and run every half hour or more often from 10 a.m., with the last at 5:30 p.m., until the Forest Service closing date in August; book on Recreation.gov. From Highway 89 at the north end of St Charles, Minnetonka Cave Road climbs eight miles up the canyon to the lower parking lot. Take a jacket. Everyone who does not, regrets it.
Other places on the map within a couple of hours.
