Rat Lake, Gallatin Canyon


Hiking To Rat Lake in the Gallatin Range of SW Montana

Location: Gallatin Canyon – Storm Castle Turnoff – Rat Lake TH
Trailhead: Rat Lake Trailhead (23.95 miles north of Big Sky)
Type: Out and Back
Distance: 1.75 miles round trip
Time: 1 hour round trip
Rat Lake Trailhead: 6330 ft
Rat Lake Elevation: 6525 ft
Vertical Gain: 230 ft

Rat Lake is an easy day hike located in the Gallatin Canyon near Big Sky, Montana. Don’t be discouraged by the name of Rat Lake, it’s a beautiful lake sitting in the deep forests of the Gallatin Range on the eastern slope of Garnet Mountain. If you’re keen to get out in the woods of SW Montana, this is a great hike to check out.

rat lake looking west
Rat Lake
Rat lake Route
The Route

To get to Rat Lake from Big Sky, head north on 191 for 17.2 miles and turn at the Storm Castle Turnoff. The Storm Castle Road, or NF-132, is a dirt road that leads you deep into the Gallatin Range. Follow the road for 6.75 miles to the Rat Lake Trailhead. The Storm Castle Trailhead is located 1.8 miles down the road. It’s home to the Storm Castle Peak Trail and the Gallatin Riverside Trail. At 3 miles, the Spire Campground is a developed campground for outdoor enthusiasts. Eventually the FS road splits. Stay to the right. It will split again, also stay to the right and you will soon cross Squaw Creek.

Squaw Creek
Crossing Squaw Creek

Soon after it crosses Squaw Creek, you will see a sign for Rat Lake. Stay left and you will find yourself at the parking area. The parking area is located at approximately 6330 feet.

rat lake
Rat Lake Parking Area
Rat Lake Trailhead
The Rat Lake Trailhead

From the parking area, follow a wide trail to the South-SouthWest. It is a rocky path that is ideal for ATVs. After a short walk through forests and meadows the trail splits and a USFS sign directs you to Rat Lake at 6525 feet.

rat lake main trail
The Main Trail

With a few more moves of the heel-toe express, you’ll see a pristine, lake. In the background we saw some incredible snow capped peaks too. The lake is much larger than expected – and during outrentire hike we did not see one single rat. Rat Lake does not live up to its name.

Snowy peaks
Snow Capped Peaks of the Gallatin Range

A well traveled, hiker’s trail circumnavigates the lake. The western side is wide open and grassy. The southern side is a bit marshy. The eastern side is well forested. The trail comes and goes but stays near the water. You will also notice several established campsites.

rat lake trail
A narrow trail circumnavigates Rat Lake

Eventually, you will return to the large, ATV trail. Follow it back to your vehicle. The entire hike is only 1.75 miles and takes about 45 minutes to an hour. The total elevation gain/loss is about 230 feet. You can also continue on the well maintained trail on the south east of Rat Lake to climb to Garnet Mountain.

rat lake looking west
Looking West

Overall, Rat Lake Hike is an easy access, dog friendly, kid friendly, walk in the woods. There is plenty of water, a beautiful mountain lake, and not many people. Enjoy your hike.


Here are some additional photos from the Rat Lake hike: