Big Timber Canyon to Twin Lakes (Crazy Mountains)

Crazy Mountains, Custer Gallatin National Forest, Yellowstone Ranger District (Halfmoon Campground trailhead, northwest of Big Timber)

Distinctly Montana calls the Crazy Mountains “Montana’s less-heralded alternative to the Tetons.” Much of the range is a checkerboard of public and private land, which Distinctly Montana gives as the reason it lacks federal wilderness protection.

Big Timber Canyon, on the east side of the range, has a Forest Service campground and trailhead at the end of its road, and Twin Lakes is a short overnight from there.

The hike

The trail starts at Halfmoon Campground at the end of Big Timber Canyon Road. The Forest Service gives directions of about 11 miles north of Big Timber on US 191, then 12 miles west; Distinctly Montana says the gravel road starts 11.2 miles north of town and runs about 14 miles. Hiking Project advises a 4x4 or careful driving for the last couple of miles, and the Forest Service says the road isn’t suitable for vehicles over 32 feet and access is limited by snow in fall and winter.

Big Timber Creek Trail #119 climbs the valley mostly along an old railroad grade, according to Hiking Project. About a third of a mile in, a spur leads to Big Timber Falls; a 2006 SummitPost report found them “Severly flooded” in June runoff. About a mile in, the trail crosses the creek on a solid bridge as the canyon narrows, then crosses again in an open area around mile 2. Hiking Project calls the next stretch “a powerful climb,” ending at the junction with the Blue Lake Trail #118 and the Sweet Grass Trail.

Distinctly Montana puts Twin Lakes 4.2 miles up the trail, with Glacier Lake another 3.4 miles beyond and the Sweet Grass Trail leading north from there. Blue Lake is a side trip: 2.8 miles to the junction, then 1.2 miles up Trail #118. Wild Montana’s volunteer crew built turnpike on this trail in 2023 and listed Granite, Blue, and Thunder Lakes farther up.

SummitPost’s 2006 party had planned on Granite Lake, found Trail #118 buried in snow in early June, and camped at Twin Lakes instead. The next day they climbed past Oasis Lakes toward Conical Peak, writing that “the view from the top looking over Oasis Lakes was worth it.” Hiking Project notes a healthy mountain goat herd and wolverine habitat in the range.

For an Absaroka-Beartooth overnight south of the Yellowstone, see Sundance Pass.

Tips

Stay on the road and trail. The Crazies are a patchwork of private and public land (Distinctly Montana); SummitPost’s group passed private land and a gate on the county road.
Go after the snow melts. SummitPost found Trail #118 buried in snow in early June.
Fill water at the campground in summer; the Forest Service says Halfmoon has potable water from Memorial Day through Labor Day.
Carry bear spray and store food properly (see below).

Camping

We found no permit requirement for camping on the Crazy Mountains’ national forest land, which is not designated wilderness. The Custer Gallatin food storage order covers the Yellowstone Ranger District from March 1 to December 1: food and scented items must be attended (within 100 feet, in sight), hung at least 10 feet up and 4 feet from the trunk, or stored in a certified bear-resistant container. Halfmoon Campground at the trailhead has 12 first-come sites.

Inside Intel: The 2006 SummitPost party camped on the shore of the eastern Twin Lake, in a small snow-free spot under the trees. It’s the only camper account of Twin Lakes we found, and it’s old, so expect conditions to differ.

Trail facts

Distance: About 8.4 miles round trip (4.2 miles each way per Distinctly Montana)
Route type: Out and back
Difficulty: Moderate to strenuous
Campsites: Dispersed at Twin Lakes; Blue, Granite, and Glacier Lakes farther on
Water: Big Timber Creek and the lakes; treat it
Permits: None reported
Bear storage: Required March 1 to December 1
Dogs: Leashed (Hiking Project)
Trailhead: Halfmoon Campground, end of Big Timber Canyon Road
Last verified: October 10, 2026

The Lowdown

Boiling water at the eastern Twin Lake:

Twin Lakes is a short, steep carry in the Crazies, so a light cook kit leaves room for the rest. See the stoves reviewers recommend.

See the picks →

Where this comes from

This page draws on the sources below, along with other guides and trip reports. Links go to the original pages.

Before you go: This page is based on published trail guides, trip reports, and reviews, along with official park and agency information where we could find it. It’s meant to help backpackers discover new trails, not to replace current, official information. Conditions, closures, permits, campsites, and water sources change, and some details here may be out of date or wrong. Confirm everything with the managing agency and check current conditions before you head out, and don’t rely on this page alone for safety or navigation. Backcountry travel involves risk.