South Fork Spanish Creek to Mirror Lake

Lee Metcalf Wilderness (Spanish Peaks Unit), Custer Gallatin National Forest (Spanish Creek Trailhead, off US 191 between Bozeman and Big Sky)

The Spanish Peaks rise at the north end of the Madison Range, and the Spanish Creek Trailhead is their northern doorway. The Forest Service calls the trailhead large and popular, and Explore Big Sky says the South Fork Spanish Creek Trail “truly offers something for everyone”: a flat creekside walk for the first two miles and an alpine lake at the top.

Mirror Lake sits at the top of the main South Fork climb, with side routes to the Spanish Lakes and Jerome Rock Lakes along the way.

The hike

Explore Big Sky’s directions: drive about 20 miles north of Big Sky on US 191, turn onto Spanish Creek Road just past Spanish Creek, and follow it about 9 miles through the Flying D Ranch to the trailhead. The trailhead has parking for cars and trailers, an outhouse, picnic sites, and three trails: Little Hellroaring (#400), Cherry Creek (#401), and South Fork Spanish Creek (#407). The Forest Service says there’s no potable water.

From the parking area, cross Spanish Creek on a small wooden bridge and turn left onto Trail #407. The first two miles are flat along the creek. Between miles 2 and 3, the trail forks: the right fork climbs Falls Creek toward the Spanish Lakes, and the main trail continues up the valley toward Mirror Lake. Hiking Project describes the Falls Creek turn as the route to the Jerome Rock Lakes Trail and the High Lakes Trail, which leads either over a pass or up to the Spanish Lakes. Its 20.3-mile loop climbs to Jerome Rock Lakes, which it calls “a worthy site for camping,” then returns by the High Lakes, Camp Creek, and Cherry Creek Trails.

Staying on the South Fork trail, Explore Big Sky says “the majority of the climb” comes in the last two miles below Mirror Lake. It puts the lake at 7.5 miles and the gain at 2,256 feet from a 6,114-foot trailhead. Hiking Project’s version of the trail runs 8.9 miles, continuing past Mirror Lake to a pass into Bear Basin or over to Summit Lake. A 2015 Backpacking Light trip report describes the descent from Summit Lake to Mirror Lake as “steep and very technical.”

The Spanish Peaks reach about 11,000 feet at Gallatin Peak, according to Explore Big Sky. The article also mentions an old Forest Service guard station that can still be rented for overnight stays.

For a Madison Range trip farther south, see Hilgard Basin.

Tips

Yield to horses. Explore Big Sky says the trail sees heavy equestrian use; bikes and motor vehicles aren’t allowed.
Wear blaze orange in fall, when hunters use the trail heavily (Explore Big Sky).
Carry bear spray. Explore Big Sky calls the Spanish Peaks common bear habitat.
Save energy for the end. Most of the climbing comes in the last two miles to Mirror Lake.

Camping

No permit is reported. The Greater Yellowstone Area wilderness order caps groups at 15 people (and 15 head of stock in the Spanish Peaks Unit), limits stays to 16 days at one location, and bans caching gear and shortcutting switchbacks. The Custer Gallatin food storage order applies on the Bozeman Ranger District from March 1 to December 1: food and scented items must be attended, hung at least 10 feet up and 4 feet out, or stored in a certified bear-resistant container.

Inside Intel: Hiking Project’s trail description calls Mirror Lake excellent for camping and fishing, and its loop description recommends Jerome Rock Lakes for an overnight. We didn’t find camper accounts that recommend a specific site at either lake.

Trail facts

Distance: 15 miles round trip to Mirror Lake (7.5 miles each way per Explore Big Sky; Hiking Project’s trail is 8.9 miles one way)
Route type: Out and back
Difficulty: Moderate to strenuous
Campsites: Dispersed; Mirror Lake; Jerome Rock Lakes and Spanish Lakes via the Falls Creek fork
Water: Spanish Creek along much of the route; none at the trailhead; treat it
Permits: None reported
Bear storage: Required March 1 to December 1
Dogs: Leashed (Hiking Project)
Trailhead: Spanish Creek Trailhead, about 9 miles up Spanish Creek Road from US 191
Last verified: October 10, 2026

The Lowdown

Cold nights under Gallatin Peak:

Mirror Lake sits near the top of a trail that climbs past 9,000 feet in the Spanish Peaks. See the sleeping bags reviewers trust for high camps.

Read the full guide →

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.