The Bears Tooth is the imposing rock spire seen from the understandably famous Beartooth Pass highway, which connects the town of Red Lodge on the east flank of the Beartooth Range with the NE entrance of Yellowstone NP. Anyone who has driven over this pass (of which nearly 20 miles of it is well above treeline) has seen the Bears Tooth, unless fog clouded the views. The feature is so appealing, the entire mountain range was named after it, which originated as an English translation from the name given to these mountains by the Crow tribe. Climbing the Bears Tooth is something the local climbers will have all done, but very few outsiders have stood on its lofty summit. Locals from Billings, Red Lodge, and a few from Bozeman consider it an enriching climb with guaranteed solitude, as the terrain calls for extensive mountain experience, and a good eye for the weather.
There are two trailheads to choose from for approaching this tower. They are the Lake Fork, and Main Fork Rock Creek Trailheads. I quote from my Beartooth Range Area page below:
Lake Fork Rock Creek Trailhead
Access to Beartooth Mountain and the Rock Lakes
From the Montana State 308 and US Highway 212 junction in Red Lodge, go 10.8 miles west on US 212 towards Beartooth Pass and turn right onto the Lake Fork Road. Go 1.8 miles on this paved road to its end at the trailhead with ample parking. The elevation at this trailhead is 7200 feet.
Main Fork Rock Creek Trailhead
Access to the Spirit Mountain Group and Glacier Lake
From the Montana Road 308 and US Highway 212 junction in Red Lodge, go west on US 212 for 11.4 miles and turn right onto FS 2421 (Rock Creek Road) and measure from this point. Follow this paved road for 0.9 miles where it turns to dirt and passing by three National Forest campgrounds. Here the road forks, take the left fork and continue on the good dirt and pass the M-K Campground at mile 2.8. Here the road becomes rougher. Continue 8 miles on this road as it drops into Wyoming and reaches the trailhead at the Montana/Wyoming state boundary at 8,700 feet. This road is passable for tough passenger cars with good ground clearance. There are many good places to pull off and camp.
Lake Fork Approach via Black Canyon Lake - 2,100 feet gain in 7.5 miles to Black Canyon Lake
It is recommended to start at the Lake Fork trailhead as the approach is much easier, with less elevation gain and much less loose talus to deal with. It is however slightly longer than the Main Fork, but this is negligible compared to the tedious nature of the Main Fork route. From the Lake Fork Trailhead, hike 5 miles up the very nice trail as it gently climbs alongside the south side of the Lake Fork of Rock Creek. At 5 miles, you will come to a large bridge where it crosses to the north side of the creek (more like a raging river). Do not cross the bridge, rather locate a trail immediately before the bridge off to the left and heading southwest. This trail starts out very nice as it weaves through open trees, but soon comes to a marshy area. Follow the now somewhat faint path through the marsh, up leftward in a small drainage, and eventually rising back into denser forest above this drainage to the right. There is a sucker trail that heads sharply right, down towards the Lake Fork partway up the small drainage. Do not follow this, but rather stay in the little creek bed. The trail will improve higher up.
Once past this section, continue on the nicer trail as it begins to parallel a larger creek above and to its left. This is the creek that drains Black Canyon Lake. When the trees open up, do not follow the trail onto the talus slope. Instead, descend 30ish feet and cross the creek on large boulders, and continue on a fainter, but nice path through the trees and near the shore of the creek, until it disappears. Enter a small meadow and follow the grass as much as possible, angling leftward, looking for cairns to show the easiest path through the large boulders looming above. The north end of the lake is almost entirely surrounded by house sized boulders, and deviating from the path of least resistance can cost you over an hour of tedious boulder-climbing! You will reach the NE corner of Black Canyon Lake where a small grassy patch offers a nice camp spot (elevation 9,240 feet). Or, you can continue around the left (east) side of the lake for an additional mile of boulder hopping and camp at the beautiful meadow at the lakes southern shore. That would require carrying the overnight gear around the lake though, and the views wouldn't be quite as impressive.
Hike up the drainage until you reach the toe of the rock glacier, and continue along the small depression on its north edge. You shouldn't have to venture too far onto the rock glacier itself, as the terrain is hideously loose. When you come to a small stream coming down from the right at about 9,800 feet, ascend the nice slopes along its left side, and pass by the 10,190 foot tarn. Continue west towards the annoying looking talus slope leading to the formidable looking col separating the Bears Tooth from the main mountain. Ascend this large talus field for 800 feet to 11,300 feet where the talus ends and the scrambling/climbing begins.
Main Fork Approach over the Spirit/Rearguard Saddle - More Elevation Gain!
This approach is a bit shorter in mileage than the one described above, but is definitely more effort, as you will need to ascend over the 11,280 foot saddle between Spirit Mountain and Mount Rearguard, then descend over 1000 feet into the large valley above Black Canyon Lake. This descent not only is covered with hideously loose talus, there is a rock glacier you'd also have to cross to get to the south facing slopes leading up towards the Bears Tooth. Then this would have to all be repeated on the return trip. If you are set on this approach however, at least do it when it's mostly snow covered, such as May-early July. From the Main Fork Trailhead, begin up the steep switch-backing trail through an old burn area and reach a nice footbridge crossing Rock Creek after 0.6 mile at 9,080 feet. Cross the bridge and continue up the trail for eight more switchbacks and locate a side trail heading off to the right (north) at 9,230 feet, a quarter mile from the bridge. There may a cairn here to mark the turnoff but don't expect one. Follow this steep but well traveled boot path along the left (west) side of this side creek for 0.35 mile to where it crosses back to the east side of the creek on large boulders at 9,600 feet. Past this crossing the slope eases and the path continues through open grass above and on the right side of the creek. The trail can be hard to follow at times but follow it to a small tarn at 9,850 feet where it once again crosses the creek back to the west side. Continue up another couple hundred feet on open grass to Shelf Lake then continue around its left (west) side and continue northward over a large, broad grassy bench for 1.2 miles to the southeast corner of Moon Lake. It's about 3.2 miles from the Rock Creek Trailhead to Moon Lake with slightly over 1,500 feet of elevation gain.
Continue around the right (east) side of Moon Lake, then up the valley towards the obvious saddle right at the base of the NE ridge of Spirit Mountain. Do not ascend to the slightly higher saddle off to the right closer to Rearguards West Ridge. Once at the saddle (which you are likely cursing if it wasn't snow covered), take in the views of the Bears Tooth directly across from you. It's 1100 feet down, which you will have to re-climb on return. Begin descending, and angle left to avoid the series of cliffs that are found below the saddle. Again, snow would make this all easier. Reach the rock glacier in the valley at 10,100 feet and traverse straight across to reach the south facing slopes leading towards the Bears Tooth/Beartooth Mountain Col. Ascend the nice, talus-free slopes for 500 feet, passing off to the left (west) of the 10,190 foot tarn, then continue up large talus for an additional 800 feet, where the talus ends at 11,300 feet directly below the formidable looking col separating the Bears Tooth from the main mountain. Here the scrambling and climbing begins.
From the end of talus at 11,300 feet, it is only another 600 feet to the summit, but plan for at least 4 hours to ascend and return this distance. The climb begins by scrambling Class 3 ledges upwards, trending rightward to connect series of rubble covered ledges and crossing right at the base of the vertical south face to reach the angled east ridge. There is one section that is quite scary and unprotected, where the ledges somewhat disappear, leaving you to traverse on a somewhat dust covered friction slab for a handful of moves with deathly exposure below. Once across this, the large ledge at the base of the south face widens considerably and it's an easy romp to the east ridge. Take solace as you won't have to return across that spot, as there is an established rappel anchor that allows you to bypass this on return. A 6 foot Class 4 move is required to actually mount the ridge, where you can then rope/rack up. Note that for the route description below, the pitches are 30 meters long.
Pitch 1 & 2 - The first two pitches are largely a Class 3-4 scramble with a few low 5th class spots mixed in. One 20 foot slab with 5.4 climbing was a little spice to get you warmed up. Rope drag will be an issue. There are slung boulders abound to use as anchors. Nothing too crazy here.
Pitch 3 - When the ridge steepens, ascend a chimney for 30 feet or so, exit right and continue up the featured face to a nice anchor on a large ledge. Class 5.6
Pitch 4 & 5 - *Money Pitches* Climb up the wildly exposed arete just above the ledge (Class 5.6), and continue up easier blocky rock to a smaller ledge with anchor. Looking above from here you will see a large overhang. Continue around to the right and climb a right facing lieback hand-crack dihedral (Class 5.8) that bypasses this overhang to the right. The dihederal more or less transitions into an awkward right facing chimney but face holds and jugs are easy to come by (Class 5.7). This section may be damp, as you are now on the colder north side of the tower. The final 30 feet to the summit eases to 5.4
Enjoy the incredible views from the top!
Camping can be found at either end of Black Canyon Lake, Lost Lake, Shelf Lake, Moon Lake, or the small tarn just below Bears Tooth. No red tape!
The Bears Tooth has been done in winter. It took a combined effort including 20 failed attempts over many years, but on March 16th, 2010, Rusty Willis and Loren Rausch finally topped out on the summit in calendar winter. The effort capped off a nearly 20 year goal, of which almost killed them at one point. The approach was done on skis, and many pitches were added, as they linked up the entire ridge extending off to the east beyond the typical start for the ascent in summer. This was done to avoid dangerous avalanche terrain on the slabs below the south face. 15 total pitches up to 5.8 rock and mixed climbing to grade 5 were done. See the report here!
For mere mortals, June-September is the typical time to climb, with July and August bringing the most thunderstorms to be aware of. Start early!