Page Type Page Type: Mountain/Rock
Location Lat/Lon: 45.02695°N / 109.59961°W
Additional Information County: Carbon
Activities Activities: Hiking, Mountaineering, Bouldering, Scrambling
Seasons Season: Summer, Fall
Additional Information Elevation: 11409 ft / 3477 m
Sign the Climber's Log


Aptly named Lonesome Mountain rises like a solitary sentinel from the Beartooth Plateau amidst a stunning array of lakes, streams, snowfields, and tundra.

A line of Montana's 12000' peaks run to the north while Wyoming's impressive Beartooth Butte dominates the landscape around US 212. Pilot Peak and Index Peak are easily visible just off to the west.

Most of the approach is through Wyoming and not until you reach Lonesome Lake, which sits at the base of the mountain, do you enter Montana. Although the effort looks like a straight shot across the open country, there are obstacles to overcome. Well into July you can encounter numerous snowfields, wide stream crossings, wet and boggy tundra, grey mud,
and lakes that have to be circumvented. Your reward though is a quality 11000' Montana summit.
Lonesome Mountain & Lonesome LakeLonesome Mountain & Lonesome Lake

If you like wide open raw country and are adverse to the crowds in Yellowstone, then the Beartooth Plateau and Lonesome Mountain might be the right fit.

Getting There

Lonesome MountainLonesome Mountain

There are two jumping off points that you want to shoot for. Either Beartooth Lake or the Clay Butte Lookout. Fortunately, both are within about 1.5 miles of each other.

Beartooth Lake and campground are located on US 212 roughly 22 miles east of Cooke City or 40 miles west of Red Lodge.

The well marked Clay Butte Lookout is located about 1.5 miles west of Beartooth Lake.

Photo credit: Bob Sihler

Summit Routes

Beartooth Lake campground
Beartooth LakeBeartooth Lake

The trail begins at the north end of the campground working its way around the east end of Beartooth Lake. When it forks, stay to the left on Trail 619 and continue around Beartooth Lake. Do not take the right fork to Beauty Lake. The trail shortly turns to the north and parallels the east side of Beartooth Butte.

Lonesome Mountain will shortly be in your sights and it will be your choice where to leave the trail and go cross country. You will have to circumvent Lonesome Lake and it is best to go around the east end.

South RampSouth ramp

The ascent route is the south ramp. Expect some routine Class 3 boulder climbing around 11000'. One way distance is roughly 5.25 miles.

A word of warning - there are 4 or 5 stream crossings to negotiate in getting around Beartooth Lake. If going in June or July, do not expect to rock hop these or go Carl Lewis. Too deep, too wide, too much water.

Clay Butte Lookout

Your starting point is the Upper Granite Loop/Lake trailhead. It is located on your left just before the U-turn leading up the final stretch of road to the lookout tower. The parking area can handle 10-12 vehicles and is obvious.

This trail works north along the west side of Beartooth Butte. Do not take the fork to Granite Lake. Once you get around the north end of Beartooth Butte, Lonesome Mountain will show itself and it will be cross country time.

As with the above route, circumvent Lonesome Lake and ascend the south ramp. One way distance is similar at roughly 5.25 miles.

NE Ridge Route
NE Ridge RouteNE Ridge Route

This Class 3 effort is certainly a route for later in the season. This ridge separates Jasper Lake to the northwest and Albino Lake to the east.

bakcast can provide more details on this scramble for those who are interested. Most likely this route involves an overnight on the Beartooth Plateau. Expect roughly 1400' of elevation gain from either lake.

NE Ridge Route photo credit: bakcast


Beartooth ButteBeartooth Butte

Beartooth Butte towerBeartooth Butte tower

From Beartooth Lake, this fortress of rock, cliffs, and towers looks impenetrable. However, the back or west side offers Class 2 routes to the summit.

From the area of the U-turn on the Clay Butte road, head east and drop into the small valley below Beartooth Butte. From here pick your best line of ascent. Easier routes can found if you move further to the north.

Beartooth Butte-- North RidgeBeartooth Butte north towers

From Beartooth's summit you can continue and launch an assault on Lonesome Mountain. There are some prominent towers to the north along Beartooth Butte. After working around these, you can immediately drop off to the east and descend grassy slopes and breaks to get off the butte.

Lonesome is clearly visible and once off Beartooth your route will closely mirror the description given in the Beartooth Lake campground route. Round trip distance will be in the 12-14 mile range.

Check out Bob Sihler's tight and thorough page on Beartooth Butte.
He has included a different and much more scenic route to this summit.
North towers photo credit: Bob Sihler.


Northwest summit 11409 Lonesome summit 11409'

Some sources list Lonesome at 11409' while others show it at 11399'. A careful look at the contours would indicate that the highest point is the summit to the northwest which does show it to be above 11400'.

A comparison with my GPS did show a slightly higher elevation on the northwest summit. Based on those two observations, it seems that 11409' is appropriate.


Beartooth Lake campground is obviously the closest. There are also 3 Forest Service campgrounds (Chief Joseph, Colter, and Soda Butte) all located just a few miles east of Cooke City.

Car camping right at the Upper Granite Loop/Lake trailhead is also an option. Backpackers routinely leave their rigs here for extended periods, so no issues. Getting one of the 4 or 5 level spots might be more of an issue.
Lonesome MountainLonesome Mountain



Children refers to the set of objects that logically fall under a given object. For example, the Aconcagua mountain page is a child of the 'Aconcagua Group' and the 'Seven Summits.' The Aconcagua mountain itself has many routes, photos, and trip reports as children.