Lost Lake (East Rosebud)

Drainage: East Rosebud
Approaches: East Rosebud bridge via Armstrong Creek — about 3.3 mi one way; roughly 2,900 ft up, no trail · From Shadow Lake — about 0.75 mi west-southwest up the connecting drainage, 630 ft up

Elevation: 9,155 feet
Fish: No FWP data
Coordinates: 45.19447, -109.68827
Bugs: Minimal on our visit

Getting there

Park by the bridge at East Rosebud. The road leading out of the neighborhood carries a no trespassing sign. Walking it is permitted. Driving a vehicle through is not.

The hike

Six miles round trip and about five hours, with almost all the work in the first half.

The climb to Shadow Lake is the hard part of the day. It is 2.5 miles with 2,240 feet of gain and no trail on any of it, which is a steep, sustained pull before you have reached the first lake.

From Shadow, follow the drainage that connects the two lakes, heading west-southwest. It is three quarters of a mile and about 630 feet up. That stretch is pleasant walking for what it is, though steep in sections, and the navigation is simple. You track the drainage up, and up, and up, until the lake comes into view.

The last part is different. As you approach Lost the ground turns into a massive boulder field, and these are not talus chunks. They are large enough that getting through them is a physical problem rather than a walking one.

Lost sits at 9,155 feet, about 630 feet above Shadow, in Custer National Forest.

Tips & safety

• The boulders are what make this hard at the end. They are big enough that an older dog will need carrying through a number of spots. Think about that before you bring one.

• The climb to Shadow is what makes it hard at the start. Off trail the entire way, 2,240 feet in two and a half miles.

• Navigation is simple. Follow the drainage west-southwest out of Shadow. There is no route finding problem here, only a steep one.

• Fishing: we did not catch anything. There is no FWP record for this lake.

• Camping: Lost sits at 9,155 feet above the boulder field, which makes it hard ground to reach with a full pack and hard to find flat ground on once you are there. Shadow below is the more realistic camp, at 8,521 feet with brook trout in it.