Grebe Lake is an intriguing option for fly fishing in Yellowstone National Park because it contains arctic grayling, a unique salmonid that is rare in the Lower 48. Known for their large dorsal fins and unique look, grayling are also aggressive feeders and take flies readily. Originally fishless, grayling from Georgetown Lake in Montana were stocked here nearly 100 years ago in an attempt to preserve the species, which was fast disappearing from Montana. Grayling thrived in Grebe Lake for years but some non-native species like rainbow trout were also introduced. In 2017 the Park service poisoned Grebe Lake to eradicate rainbow trout and then restocked the fishery with both grayling and west slope cutthroat trout. Grebe is fairly large for a mountain lake, at just over 150 acres. Portions of the shoreline are marshy and tough to wade, but much of the lake has a grassy shore with a firm bottom, offering easy wading and casting.
As with many mountain lakes, Grebe fishes best early in the season and starts to slow down as hot summer weather pushes fish into the depths. The trail to Grebe will be snow covered or extremely muddy when the park fishing season opens and usually be clear by the middle of June. How soon you can get to Grebe Lake depends on last winters’ snowfall and your tolerance for snow and mud. The fishing will be red hot early on in June and gradually slow in July. Subsurface fishing is often best, which can be done on a floating line with an assortment of small split shot or a slow sinking lake line. General patterns like Wooly Buggers and Bead Head Nymphs work well, as do more specific lake patterns like Damselfly Nymphs or Scuds. Allow your flies to sink a bit and retrieve them slowly, experimenting with both the speed and length of your strip. Grebe sees a fair amount of hatch activity as well. Since the fish are typically not very picky, general patterns such as Parachute Adams, Griffiths Gnats, and Renegades work well. While fish are found cruising throughout the lake, inlets, outlets, and structure in the water are always a good starting point.
Grebe Lake is reached via a 3 mile (one way) hike, which fortunately is quite flat. The trailhead is located on the north side of the road between Norris and Canyon: approximately 8 miles from Norris and 4 miles from Canyon. The trail leads to the south shore of the lake, but it is easy to walk around in either direction, avoiding the marshy areas in search of fish.