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Backpack the Warren Pass Loop

Anaconda, Montana



12 miles

Elevation Gain

2000 ft

Route Type



Added by Joshua Contois

Pristine alpine ecology of the continental divide with ample wildlife viewing opportunities from megafauna including deer, elk, bears, moose, and bighorn sheep to smaller animals including pikas, fishers, fox, and beaver. Wildflower blooms well into late summer, with clear, dark night skies, excellent trout fishing and solitude - one of the least frequented wilderness areas. There is an optional side trip to peak bag the 10,468 ft Warren Peak.

Often overlooked due not to its lack of scenery, but rather because of its proximity to both Yellowstone and Glacier National Parks, the Anaconda-Pintler Wilderness in southwest Montana is a haven for hikers and backpackers seeking a true wilderness experience. Established in 1964, the area straddles the Continental Divide of the Anaconda mountain range. In fact, the 45-mile stretch of the Continental Divide Trail that traverses the range is widely regarded as one of the trail's most scenic sections. Encompassing high peaks, wide valleys, and glacial moraines, the wilderness is a feast for the senses. A heavy winter snowpack feeds sparkling lakes and rolling steams that teem with several species of native and introduced trout. Wildlife abounds, and the keen observer might encounter an occasional grizzly, moose, elk, mule deer, or bighorn sheep.

The Warren Pass Loop is a pristine example of this wonderful landscape both for its scenic beauty as well as its accessibility. Just past the East Fork Reservoir, a 16-mile well maintained dirt road leads to the trailhead. Be sure to sign in at the register.

The trail begins gradually, crossing into the wilderness area at Carpp Creek, only a quarter mile from the trailhead. Stay right at the first fork, and follow the trail along a gradual downward slope for about a mile through a primarily Lodgepole Pine forest. The trail is well maintained and crosses several small streams.

At the second fork, the trail bears left and begins a moderate ascent through a mixed coniferous forest of Lodgepole Pine, Subalbine Fir, and Engelmann Spruce for approximately two miles. The trail culminates at a bridge crossing a stream emanating from the nearby Carpp Lakes. In the summer months, expect this small wetland to be filled with dragonflies, frogs, and plenty of songbirds. Just a few hundred yards past the bridge lies Lower Carpp Lake. In reality, the lower lake is not much more than a glorified mosquito pond, so there is no need to linger. Carpp Lake proper is only another quarter mile past the lower lake.

There are plenty of campsites located located along 27-acre lake, each wonderfully removed from the others and all of them sharing inspiring views of the nearby Warren Peak. Due to fragile wetlands and a ban on fires at the upper lake, it is highly recommended to spend the night at the already impacted Carpp Lake. Spend the afternoon casting some lines in hope of catching some of the many species of trout inhabiting the lake. Sunset creates a wonderful alpenglow across Warren Peak, and when afternoon winds die down the lake becomes mirror reflective. The muffled hush of the crepuscular hour brings with it excellent opportunity to observe ungulates drinking and foraging along the opposite shore, frogs and toads pontificating to potential mates, and to this observer, a fisher chasing a chipmunk. As the sun sets, the Milky Way debuts in spectacular form.

The following morning, after a warm breakfast and some cowboy coffee, it's time to hit the trail. For nearly two miles, the trail switchbacks across a moderately steep grade through dense forest and multiple stream crossings and rocky outcroppings. Emerging in an open wetland, Warren Peak looms over Upper Carpp Lake. Whitebark Pine abounds, as does a chorus of Clark's Nutcrackers. The occasional bighorn sheep can be seen on the rocky talus across the lake. Adventurers seeking to summit Warren Peak can do so from here, provided they can avoid the false summit on the western slope.

After a rest to enjoy the scenery, it is time to continue the additional mile up moderate switchbacks to Warren Pass. From the pass, Warren Peak dominates the view to the west, and occasional vistas can be had to the north through the snags of Whitebark Pines. Summiting the pass, the trail continues south into the Maloney Basin. Careful observes might see pikas dashing about the scree slopes during the descent into the basin.

The hiker is immediately rewarded with sweeping vistas and flower filled meadows as the trail descends rapidly. The trail is overgrown in some places, so it is easy to get lost. Be sure to keep track of one's surroundings and a topographical map is extremely useful in this section. The trail is quickly enveloped by dense forest, punctuated by spots of sunlight until reaching black bear meadows. Several large pines provide ample shade for an afternoon snack or late lunch.

From this point on, the trail continues a regular descent for the next six miles back to the trailhead. Water crossings are less frequent, so be sure to filter some if you're getting low. Keep an eye out for grouse, skunk, fox, and deer.

Note: The trail sees heavy stock use in the summer months by locals, which creates many muddy patches. Always yield to pack animals.


  • Carpp Lake Trailhead: 46.030679, -113.436980
  • Carpp Lake: 46.014103, -113.453157
  • Warren Pass: 45.993536, -113.455362
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