The Trail Turning Big Timber Canyon Into a Way North Through the Crazies

Where can you go from the Halfmoon trailhead besides farther up Big Timber Creek? For as long as most people around Big Timber have been driving out Big Timber Canyon Road, the honest answer has been nowhere else. The canyon is a way in, and the only way out has been back the way you came.

That is changing. The Custer Gallatin National Forest is building Sweet Trunk Trail No. 274, a new route that starts in Big Timber Canyon at Halfmoon Campground and runs north toward Sweet Grass Creek. For more than five years the trail was a line on proposal maps. Now it has a contractor and an end date for the contract, and work began this year at the trailhead Big Timber already knows.

One door on the east side

The trail makes sense once you see how the east face of the Crazies has been divided. When the connecting trail was first proposed in 2020, the Bozeman Daily Chronicle's timeline of Crazy Mountain access disputes described Big Timber Creek as "the only public access point on the east side." The reason was ownership. Public and private sections alternated across the range in a checkerboard, so an obvious route on a topo map could cross several private parcels on the ground.

Todd Orr, the Custer Gallatin's trails engineer, described the old problem and the fix in an August 2026 episode of the Forest Service's Forest in Focus podcast:

"In the past we had the checkerboard or the mixed public and private lands. And so now with this consolidation and land exchange, most of the trail is on public land, and we have a much easier access for users like stock users, horse groups, hikers."

The finished trail will stay mostly on public land and cross private ground on a couple of short easements. So Halfmoon stops being a dead end and becomes the southern trailhead of a route along the east face of the range.

The trade that cleared the route

The consolidation Orr describes is the East Crazy Inspiration Divide Land Exchange. The Forest Service signed the final decision on January 17, 2025. The agency gives up about 3,855 acres of national forest land and takes in about 6,110 acres of private land from six landowners, so public acreage grows by roughly 2,255 acres overall. Montana Free Press reported that five of those landowners hold land in the Crazies and the sixth is the Yellowstone Club in Madison County, which has long wanted access to Eglise Peak for expert ski terrain.

Several pieces of the decision point directly at Big Timber Canyon and the new trail:

The Smeller Lake parcel was owned by Crazy Mountain Ranch, which Montana Free Press notes is known locally as the Marlboro Ranch. Under the decision's cash equalization strategy, the exchange proponents donate that parcel and also pay for trail and trailhead construction. The new trail at the canyon is part of the same package.

The exchange also covers access to the range's highest summit for one group. KTVQ reported in August 2025 that the deal includes a permanent easement giving Crow tribal members access to Crazy Peak. The peak itself is privately owned, so the easement applies to Crow members, not to the general public.

Built from the Halfmoon end outward

The Forest Service first posted the construction job on June 1, 2026. According to the federal contract record for Sweet Trunk Trail #274, it was awarded on August 5, 2026 to BO Trails for $604.8K. The contract started August 4, 2026 and could run until October 16, 2028.

Orr described the schedule in seasons. The contractor gets "part of this season and then the next two summers," which means the rest of 2026 plus the summers of 2027 and 2028. He also explained why the work gets slower as it goes:

"It's access from big timber canyons. So as it gets farther back in towards Sweetgrass, it's going to be a lot more work for the contractor to be moving back and forth."

The whole job is supplied from Big Timber Canyon. Each mile north of Halfmoon adds travel for the crews, so the first stretches go in fastest and the Sweet Grass end comes last. Orr hoped to get "a big part of it done this year if the weather holds" and to finish within three years "and possibly sooner," depending on rock, terrain and weather. The Forest Service has described the trail as under construction, and the agency said in the episode that it will post updates as construction continues.

What the finished trail is designed for

Orr gives the trail as about 20 miles, with tread about three feet wide, a number of switchbacks, several stream crossings, and sections in and out of steep canyons that look out over the valley and up at the peaks. It will be nonmotorized, open only to hikers and stock or horse travel.

Orr named three uses he expects:

• A multi-day loop. Go up Big Timber Canyon, follow the ridge north, come down Sweet Grass Creek, and camp along the way.
• Pack-in hunting. Hunters can take horses farther in to camp and hunt elk, or possibly sheep or goats.
• High-country day use. Hikers and photographers get easier access to high elevations and views.

The loop idea goes back to the original proposal. In 2020, the Chronicle timeline reports, linking Big Timber Creek and Sweet Grass Creek was expected to tie into existing trails and create a 40-mile loop, along with a larger parking area at the trailhead near Halfmoon. The 2025 decision includes that trailhead work: a redesign of the Big Timber Canyon Trailhead to handle the parking the new trail is expected to bring. The decision expects more visitors at the Big Timber end, and it puts the parking there.

The other side of the range has done this before

The west side of the Crazies went through a similar change a few years earlier. The Forest Service rerouted the old Porcupine Lowline Trail and renamed it the Porcupine Ibex Trail. Montana Public Radio reported in October 2019 that a new section of nearly three miles had opened to hikers, horseback riders and mountain bikers. A lawsuit challenged the reroute, and on April 8, 2024 the Ninth Circuit affirmed the judgment for the Forest Service, as Montana Free Press covered.

On both sides the approach has been the same: move the trail onto land the public can use. Sweet Trunk differs in scale. It is about 20 miles of new trail, and it is starting at the east side's one established public trailhead.

Halfmoon between seasons

Through the winter, the canyon looks as it always has. The Forest Service lists Halfmoon Campground as open year-round, with access limited by snow in fall and winter. The route is 11 miles north of Big Timber on US 191, then 12 miles west on Big Timber Canyon Road. The campground sits on Big Timber Creek and offers hiking and horseback trails, waterfalls nearby, fishing, and the chance to see mountain goats from camp.

The contract allows work through two more summers, in 2027 and 2028. Construction will move north from the Halfmoon trailhead toward Sweet Grass Creek, starting from the parking area that people from Big Timber already use.

Public access is one of the first things buyers ask about on land near the Crazies. Trailheads, easements and nearby public sections all affect what a property offers. If you own acreage in the Crazy Mountain foothills and want to know how the changes around Big Timber Canyon affect your land, Stacie Wells can walk you through it privately. Request a Confidential Valuation.