Garnet Mountain – 8,245′ – Gallatin Range – MT


Hiking Garnet Mountain in the Gallatin Range of Montana

Location: Garnet Mountain Gallatin Canyon, Gallatin Range, Montana
Rating: I Class 1
Type: Out and Back
Trailhead: Storm Castle Trailhead
Distance: 8 miles
Time: 4 hours
Elevation Storm Castle TH: 5450′
Elevation Garnet Mountain: 8245′
Total Elevation Gain: 2850′
Lat/Long: 45°25’36″N, 111°12’23″W
Maps: USGS – Garnet Mountain, Beartooth Publishing – Bozeman Area or Big Sky Area


Garnet Mountain stands at 8245′ in the Gallatin Range of SW Montana. There are several routes to the top of Garnet Mountain. On a cold morning in late October I opted to hike the Garnet Mountain Trail leaving from the Storm Castle Trailhead to the summit of Garnet. The trail climbs steadily for the entire ascent and offers outstanding views of the surrounding mountain ranges. It’s a lovely day hike through grizzly terrain that can be completed in 3 to 4 hours.

Garnet Mountain and Storm Castle
Crossing the Gallatin River – Garnet Mountain is the mountain on right

To reach the Storm Castle Trailhead. Head north from Big Sky for 17.2 miles. After passing Beckman Flats on Highway 191, take a right onto USFS Road 132. Cross the Gallatin River and turn right. The well maintained dirt road passes a USFS Helibase and parallels the Gallatin River for 1.8 miles. Shortly after passing the Castle Rock Baptist Bible Camp turnoff, the Storm Castle Trailhead parking is on your left. This parking allows access to Storm Castle Peak, Gallatin Riverside Trail, and Garnet Mountain, but there is always plenty of parking.

Storm Castle Trailhead
Storm Castle Trailhead – Plenty of Parking

The Garnet Mountain Trail #85 leaves the parking area to the south on the north side of Garnet Mountain. It immediately crosses a bridge over Storm Castle Creek. This is the last water you will see for the entire hike, so fill up the bottle and top off the dog. Storm Castle Creek was formerly known as Squaw Creek and may be called either depending on which map you use. Be sure to read the signs at the bridge .

Garnet Mountain in the Gallatin Range, MT
Crossing the Bridge. What’s the note on the bridge say? Giant Grizzlies in area.

On my trip, there was a warning of a “Giant Grizzly” a few miles up the trail. It encouraged me to make lots of noise. My dog, River was armed with his bell. I had a BD trekking pole, bear spray, and an endless collection of “Hey Bears!” and “Aaaa-O’s.” We were set. The Garnet Mountain Trail climbs steadily from the get go. It works through the thick forests of the Gallatin Range. It was cold as we cruised through the shade of the northerly aspects which were covered in a nice green moss. At 0.3 miles the trail splits. The right fork goes on the Gallatin Riverside Trail and the left continues the calf burning ascent toward Garnet Mountain.

Garnet Mountain in the Gallatin Range, MT
Garnet Peak or Gallatin Riverside Trail?

The trail meanders and switchbacks along the western flank of Garnet Mountain. Most of the trail leads through dense Douglas firs and lodgepole pine forests. Outcroppings of limestone stand out. There are large, open meadows that offer glimpses of views you’ll enjoy later. One quick jaunt across a meadow rewards you with cool views of Storm Castle Peak. If you know where to look you can spot rock climbs like Gallatin Tower and the top of Skyline through the trees. The single track trail covers approximately 3 miles before it hits another trail.

Garnet Mountain in the Gallatin Range, MT
Beautiful open meadows
Storm Castle Peak
Storm Castle Peak
Garnet Mountain in the Gallatin Range, MT
Cool trail
Garnet Mountain
Looking Down Toward Gallatin Tower and Top of Skyline Rock Climbs

At this junction, you will be on the south side of the mountain. If you turn right and go downhill, you can go to Pioneer Lakes or head toward Rat Lake (another common route up Garnet Mountain). If you go uphill to the left, you will continue on trail 79 to the summit of Garnet Mountain and the Fire Lookout. The quick left turn takes a steep, ATV trail for 0.8 miles to the top. After you pass through a fence, you can almost see the Garnet Mountain Fire Lookout Tower. After 4 miles and 2850′ vertical gain, you’re almost there.

Garnet Mountain in the Gallatin Range, MT
There’s a fork in the trail
Garnet Mountain in the Gallatin Range, MT
Nice wide ATV trail
Garnet Mountain in the Gallatin Range, MT
It’s a gate.

The final approach travels across wide open meadows that must have pristine wildflower potential in late spring – not so in late autumn. The Garnet Mountain Fire Lookout Tower is located at the summit of Garnet Mountain. The Garnet Mountain Fire Lookout was originally built in 1930, but the current structure is from 1962. It’s in a prime location to overlook the Spanish Peaks, Gallatin Range and beyond. I can only imagine the sunrise and sunset potential of this place. The Garnet Mountain Fire Lookout Cabin sleeps four and is complete with tables, wood stoves, a wrap-around deck, and views galore, but be sure to bring your own propane. The cabin is frequently booked as it only costs $30 per night. You must reserve your night at least 3 days in advance through the Forest Service or It’s open year round.

Garnet Mountain Fire Lookout Cabin
The Garnet Mountain Fire Lookout
Garnet Mountain Fire Lookout
Inside The Garnet Fire Lookout
Garnet Mountain Trail
Room With a view

The panoramic views are breathtaking. Gallatin Peak, the king of the Spanish Peaks, had a new winter white coat on it. The far shores of Lava Lake and it’s drainage, Cascade Creek, dominate the view to the southwest. You can see all the way up Storm Castle Creek to the Hyalite Ridge and Alex Lowe Peak. Across the valley Storm Castle Peak beckons. A sharp eye can find The Sentinel. The vastness of this area will make you feel tiny.

Garnet Mountain in the Gallatin Range, MT
The Gallatin Range
Garnet Mountain in the Gallatin Range, MT
The Madison Range
Garnet Mountain in the Gallatin Range, MT
The Sentinel – 9945′
Gallatin Peak, Spanish Peaks
Gallatin Peak, the King of the Spanish Peaks
Storm Castle Peak Gallatin Range
Strom Castle Peak and Beckman Flats

After soaking it all in, the best way home is back the way you came. On the uphill it was all uphill. So, on the downhill, it’s all downhill. Moving fast downhill, hooting and hollering, and managing the dog, means you can get back to the trailhead quick. Just watch out for those grizzly bears.

Garnet Mountain
Garnet Mountain on Gaia GPS

Overall, the hike up Garnet Mountain Trail was a superb way to spend a day. The trip totaled 7.95 miles and 2850′ vertical gain in 3 hours. Next time I go, I will definitely book the Garnet Mountain Lookout. I really appreciated the views of the area, especially after doing many of the other hikes. Montana rocks.


Here are additional images from hiking Garnet Mountain in the Gallatin Range:


Garnet Mountain was hiked on October 28, 2014.