Page Type Page Type: Mountain/Rock
Location Lat/Lon: 45.16800°N / 109.55211°W
Activities Activities: Hiking, Mountaineering, Trad Climbing, Toprope, Bouldering, Scrambling, Skiing
Seasons Season: Summer
Additional Information Elevation: 11052 ft / 3369 m
Sign the Climber's Log


Grass Mountain is located in the Beartooth Mountains of southern Montana. Although Grass Mountain is above 11,000 feet, the peak is dwarfed by some of its neighbors and sees little attention and seems to be seldom visited. We climbed this mountain on a “rest day” after climbing some of the more strenuous nearby peaks in the Beartooths, so it makes a nice "rest day" climb or a nice realitively easy 11,000+ foot peak although there are many challenging routes available as well.

Although the mountain is perhaps not as spectacular as some of the higher and more rugged peaks in the Beartooths, Grass Mountain offers fine views of the more rugged peaks and is easy to access and climb. Like most other peaks in the Beartooths, Grass Mountain is surrounded by beautiful meadows and lakes, although some of the eastern ramparts of the mountain were burned by a forest fire in the summer of 2008.

The mountain is somewhat one of contrast. Some faces and slopes of the mountain are gentle (but with interesting rock formations on top), while some are steep and vertical. The north and south sides are mostly gentle, while the east and west sides are steep. Some of the granite crags and spires on the east side of the mountain would make fine rock climbs as much of the rock is solid granite.

Climbing Grass MountainClimbing Grass Mountain on August 28 2009. Whitetail Peak can be seen in the left background while Elk Mountain is far right with Lake Mary below.

Getting There

West Fork Rock Creek Trailhead

From the south side of Red Lodge, look for “West Fork Road” which heads west from Highway 212. West Fork Road is not far north of the Ranger Station and close to the Yodeler Inn. One on the west Fork Road (Forest Road 71), stay on the main road and follow it for about 14 miles to the trailhead. This is a good gravel road.

Grass MountainThese are some of the crags of Grass Mountain as seen on August 29 2009 from West Fork Rock Creek.

East Rosebud Trailhead

Make your way to the small hamlet of Roscoe on Highway 78 which can be reached from Columbus on the north or Red Lodge on the south. From the north end of Roscoe, turn west on Rosebud Road and then after about seven miles, head south on Rosebud Lake Road. This is about 14.5 miles from Roscoe and is on good gravel roads.

Routes Overview

South Ridge via Lake Mary

This is the route we took up the mountain. It is an easy route, but is perhaps not quite as easy as the route from the north. From the West Fork of Rock Creek Trailhead, the route follows the West Fork Rock Creek to the Lake Mary turnoff, follows the trail to Lake Mary and then climbs the steep southwest slopes to the gentle south ridge and thus to the summit.

This route is about 15 miles round trip and can be done in one long or an easy 1.5 days.

Climbing Grass MountainKessler on a gentle section of the south ridge of Grass Mountain.

North Slopes via Red Lodge Creek Plateau

We didn’t do this route, but on both the map and from our observations from the summit this is probably the easiest route to the summit, albeit would be less scenic than the route from Quinnebaugh Meadows and Lake Mary. From the West Fork of Rock Creek a trail ascends to the Red Lodge Creek Plateau where the gentle north side of Grass Mountain is easily accessible.

This route is 12 miles round trip and could be completed in one day. You could also make a loop hike combining this route with the route from Quinnebaugh Meadows and Lake Mary.

Gentle North SlopeThis is the very gentle north slope of Grass Mountain as viewed from near the summit.

Other Routes

There are many other possible routes on this mountain. The north slopes area accessible by trail from East Rosebud. The same is true for Crow Lake and the West Face. The West Face appears that it would make a good spring snow climb and as mentioned in the introduction, the east face crags could offer some fine rock climbing.

Crow LakeLooking down the steep west face of Grass Mountain.

Red Tape

Grass Mountain is located in the Absaroka/Beartooth Wilderness. Rules and regulations can be viewed by clicking the link below:

Absaroka-Beartooth Wilderness


There are good campsites and campgrounds along the West Fork Rock Creek Road. There are also good backcountry campsites at Quinnebaugh Meadows, Lake Mary and Crow Lake as well as at other scattered locations.

SunsetThis is the sunset as viewed from our camp along the West Fork of Rock Creek.

When to Climb

July through September is the normal time of year to climb, but this is probably one of the safer mountains for a winter ascent in the Beartooth Mountains. The road is not plowed to the trailhead in winter though.

As mentioned, there could be some fine snow climbs on the wet face of the peak in spring and early summer.

Descending Grass MountainDescending back to timberline on the slopes of Grass Mountain in on August 28 2009. Lake Mary is below.

Mountain Conditions

For current road and trail conditions, contact:

Red Lodge Ranger Station
6811 US Highway 212
Red Lodge, MT 59068-9581
(406) 446-2103‎


Weather and climate data for Cooke City at 7560 feet elevation is below. *National Weather Service Data 1967-2009. Expect higher elevations to be about 10 degrees colder than Cooke City, but the data below should give you a good idea of average conditions in the general area.




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.