Grotto Falls is a 35-foot waterfall on Hyalite Creek in Hyalite Canyon, Gallatin County, Montana, in the Custer Gallatin National Forest south of Bozeman. It sits at about 7,145 feet at the end of a short, wide trail rated easy.
The falls
Hyalite Creek drops in a single horsetail. Lidar data puts the drop at about 35 feet; earlier surveys listed 40 feet. Above the falls, upper Hyalite is a landscape of alpine cirques, lakes and dark volcanic cliffs.
Getting there
From Bozeman, follow South 19th Avenue for about 6.5 miles, then take Hyalite Canyon Road to the marked trailhead at the road's end. The Forest Service lists the Hyalite Creek Trailhead as having a pit toilet but no drinking water. The Grotto Falls trail runs alongside Hyalite Creek Trail #427. Distances vary by source: the out-and-back is 2.4 miles with 278 feet of gain (easy), one source measures 1.2 miles one way with 242 feet of gain, and another gives 1.25 miles and 170 feet of climb on a wide dirt trail. The route has disabled access, with a maximum grade of 25 percent.
When to go
Hyalite Canyon Road is closed to vehicles each spring; in 2026 the closure ran from March 31 at 6 p.m. until May 15. May through October is the recommended season, and the trail is very popular in summer. In winter the frozen falls are used for ice climbing.
On site
A picnic table and a bench sit near the falls, and the creek forms pools below them that draw swimmers. The trail is dog-friendly. Ice climbing here carries real risk: on November 25, 2023, a 36-year-old climber died after a fall at Grotto Falls.
History and name
The Montana State University Library holds a P.C. Waite photograph of Grotto Falls in Hyalite Canyon dated 1896.
Nearby
The trail continues up Hyalite Creek toward Arch Falls, about 0.6 miles away, Champagne Falls, about 1.9 miles, and Hyalite Lake. Twin Falls is about 0.8 miles away. Bozeman is about 17.3 miles to the north.
Distances are straight-line.