Minnetonka Cave

Useful Information

Location: Caribou-Targhee National Forest, St. Charles Canyon northwest of Bear Lake. 15 km west of St. Charles, on Forest Road 412.
Open: Memorial Day weekend to Labor Day daily 10-17:30, tours every 30 min.
Fee: Adults USD 8, Children (6-15) USD 6, Children (0-5) free, Family (2+*) USD 32, Golden Age Passport holders USD 3.50.
Groups (30+): 10% off.
Credit cards not accepted.
Classification: SpeleologyKarst Cave Mississippian limestones.
Light: LightIncandescent Electric Light System
Dimension: T=4 °C, A=2,346 m asl.
Guided tours: D=90 min, L=800 m, St=444, V=34,000/a[2010].
Photography: Flash photography allowed.
Address: Minnetonka Cave, Montpelier Ranger District, Caribou-Targhee National Forest, 322 North 4th Street, Montpelier, ID 83254, Tel. +1-208-847-0375.
Information and reservations: Tel: +1-435-491-0618.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1907 cave discovered by Ed Arnell while hunting a grouse.
1930s developed by the WPA and opened as a show cave.


Minnetonka Cave is said to be the longest cave of Idaho, which means the longest cave operated as a show cave. It is also one of the highest, with an entrance elevation of 2,346 m asl. This cave is famous for various speleothems, like stalactites, stalagmites, soda straws, cave bacon, and the rare helictites. The biggest chamber seen on the trip is the Ballroom, which is more than 100 m long and 30 m high. The tour path crosses nine chambers and includes a total of 444 stairs. Minnetonka Cave is operated by the forest service.

The cave was discovered by a frontier woodsman named Edward Arnell. According to legend he was working to help construct a saw mill in St. Charles Canyon. When was out hunting, he shot a grouse. The bird fell close to the cave entrance and he felt cool air when he collected the bird. He returned with friends and torches the following day to explore the cave. The cave was named after the American Indian word Minnetonka meaning "flowing water."

The begin of the season of Minnetonka Cave is weather depending. If snow conditions allow, it is typically between Memorial Day weekend and the first weekend in June. From late June the cave is visited by a high amount of visitors, which may cause hour long waits. Tickets are sold on a first-come first-served basis, the trick is to buy a ticket early in the morning.

There is no electricity at the cave. The cave light is made by a propane-powered 250-kilowatt generator.

Five different species of bats hibernate in the cave. One is the Townsend's Big-eared Bat (Corynorhinus townsendii). So far there is no White Nose Syndrome (WNS) at Minnetonka. To keep it so, visitors are requested not to wear clothing or hand carried items that have been in any other cave or mine.

The cave is reached on Minnetonka Cave Road which follows St. Charles Canyon from St. Charles to the west. On some 15 kilometers it climbs more than 500 m. After some nine kilometers is a small parking lot on the left and on the right starts the Blue Pond Spring Trail which leads to the nice karst spring Blue Pond Spring. As typical for karst springs, it contains a high amount of limestone, hence the blue colour. It is surrounded by rocks of the Ordovician Garden City Formation. After four more kilometers the canyon divides into three forks. Foot trails lead further up into the forks of the canyon. The road to the cave loops back on the mountainside to the cave on the southern slope of the canyon.