Prospect Lake
Drainage: Boulder
Approaches: Approximately 17 miles round trip from the Fourmile trailhead, with roughly 3,800 feet of climbing. No trail above Silver Lake.
Elevation: 9,617 feet
Fish: Yellowstone cutthroat, common and self-sustaining. Montana FWP.
Coordinates: 45.36663, -110.35922
Bugs: Never bad.
Getting there
Everything up to Silver Lake applies here first, and Silver is where we camped.
From there it runs northwest, about a mile and 580 feet of climbing, and it took us an hour on day packs. FWP describes it as following the left fork of the inlet stream up from Silver for about a mile, which lines up with where our track went. There is no trail.
The grade is steady rather than steep. We picked up most of the height in the middle half mile.
The hike
Prospect is 6.8 acres and 30 feet at the deepest, sitting about 480 feet above Silver.
The cutthroat here have the same history as Silver's. Prospect was part of the Upper Boulder Yellowstone cutthroat restoration, gill nets pulled the rainbows out between 2007 and 2009, and the lake was stocked until 2012 when the fish became self-sustaining. FWP's 2015 survey took 37 fish averaging 10.1 inches, 11 of them caught by angling over four hours. In 2020 they got 3 fish averaging 13.5, and picked up several small cutthroat by angling the pond in the outlet.
FWP notes the chance of running into other hikers here is pretty good, and the camping is fairly rocky with little firewood.
This is also the way through to West Boulder. From Prospect the route keeps going north and climbs to a pass at 10,142 feet, which is another hour above the lake.
Tips & safety
Navigation: No trail above Silver. Northwest up the inlet drainage, about a mile.
Camping: Fairly rocky with little firewood. Silver has the better camping and is only a mile below.
Fishing: Self-sustaining cutthroat running 10 to 13 inches. FWP has caught them by angling on two separate surveys, including out of the pond in the outlet. Fishing was good.
Bugs: Never bad.
