Lost Lake Trail

Overview

A classic Beartooth outing: roughly 10.5 miles round trip with about 1,300–1,350 feet of gain to a clear, fishy lake tucked beneath big country. The grade is steady rather than steep, so strong hikers can move quickly, but it’s still a long day. Expect a well-built path and frequent creek sounds as you follow the Lake Fork of Rock Creek.

Route and Highlights

From the Lake Fork Trailhead, the trail climbs gently up a glacial valley through lodgepole pine and aspen, with meadows, waterfalls, and rock walls for company. Around 3.6 miles, a short spur reaches Broadwater—an expanded section of the creek—an easy turnaround for a shorter 7.4‑mile day. Near 5 miles, watch for the left spur to Lost Lake; it can be easy to miss. If you cross a second bridge, you’ve gone too far—backtrack a few hundred yards. The lake sits at about 8,515 feet with rugged views toward Thunder Mountain and the high Beartooth country.

Scenery, Geology, and Wildlife

This valley was carved by Pleistocene ice, leaving hanging valleys and a necklace of lakes. Bedrock here is among the continent’s oldest granitic and metamorphic rocks, with deep time on full display in the polished slabs and cliffs. Wildlife is a real draw—moose frequent the meadows and creek environs, and deer, elk, and bald eagles are regulars. Give moose serious space and keep your head on a swivel in brushy stretches.

Fishing

Lost Lake is known for cutthroat trout and Arctic grayling. Ultralight setups and small midges can be productive, and the far side of the lake sees less pressure. Always follow local regulations and practice clean angling.

Best Time to Hike

April through October is the sweet spot, but lingering snow can show up early and late. Summer brings wildflowers and long light; start early for cooler temps and quieter shores. Afternoon light kisses the cliffs above the lake—great for photos. The highway can see weather-related closures, especially shoulder seasons, so confirm road and trail conditions before you go.

Logistics and Tips

• Distance is TOTAL for the out-and-back. Plan 4.5–5 hours moving time, more with breaks.
• The spur to Lost Lake is sometimes unsigned—download an offline map so you don’t miss it.
• Dogs are allowed on leash. Expect some stock use; step off on the downhill side for horses.
• Bugs and some horse manure are common in summer. Carry layers and rain gear; storms build fast at elevation.
• Past flooding has temporarily altered access at times; check current status if bridges or trailheads are in flux.

Getting There and Parking

From Red Lodge, drive about 10.6 miles southwest on US 212 (Beartooth Highway), turn right on Lake Fork Road, and continue roughly 1.5–1.8 miles to the end. The paved road leads to a large trailhead lot with straightforward access.