US lakes & pondsUS lakes & pondsSurface area: The USGS National Hydrography Dataset outline (NHD Permanent ID 128099028).
The red circle marks Grasmere Reservoir.
Towns and counties: U.S. Census Bureau boundaries overlaid on the USGS lake outline (Idaho: incorporated places touching the lake, otherwise the nearest one).
Official IDFG pages. Rules and fees change; check before you go.
Built only from the data on this page: official access lists, OpenStreetMap beaches and trails, campground listings, state and USGS invasive-species records. We don't rate crowds or water quality.
Stocked by the state: Cutthroat trout, Rainbow trout (2016–2026, 11 years; 253,701 fish in all, fry included)
Source: Idaho Department of Fish and Game, Idaho Fishing Planner stocking records (releases into Grasmere Reservoir, Owyhee County, since 2015). These are stocking records, not a full fish survey; other species also live here.
No public access sites are listed for this water in the OpenStreetMap boat ramps (no statewide agency ramp layer used) data.
Shoreline: USGS National Hydrography Dataset (NHD Waterbody, Permanent ID 128099028), public domain. State outline: U.S. Census Bureau TIGERweb. Points: OpenStreetMap boat ramps (no statewide agency ramp layer used). Interactive map: Leaflet with © OpenStreetMap contributors. Not for navigation.
The closest airport with scheduled passenger flights to Grasmere Reservoir, plus larger airports within about 150 miles:
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Airports with scheduled airline service from OurAirports (large and medium airports); larger airports are FAA large, medium and small hubs by FAA CY2025 enplanements ("major airport" = FAA large hub). Distances are straight-line from the lake's center, not driving distance; road routes are longer.
Live from the National Weather Service API for the lake's coordinates (42.3597, -115.9064). The nearest station may be several miles away. NWS forecast for Grasmere Reservoir. No live water-temperature sensor is shown because we haven't found a public one for this lake.
Based on solunar theory, an estimate. Major periods (about 2 hours) center on when the moon is directly overhead or underfoot; minor periods (about 1 hour) center on moonrise and moonset. The 0–100 activity score rises during those periods and gets a boost near sunrise and sunset and around the new and full moon. Weather, water temperature and pressure often matter more. Sun and moon times are calculated in your browser from the lake's coordinates with standard astronomy formulas, shown in MT (America/Boise), and accurate to within a few minutes.
Grasmere Reservoir covers about 29 acres in Bruneau, Idaho (Owyhee County).
IDFG fish stocking records lists Rainbow trout and Cutthroat trout.
Grasmere Reservoir touches Bruneau in Owyhee County, Idaho.
Know Grasmere Reservoir? Tell us about the launch, parking, where they're biting or anything a first-time visitor should know. Tips go privately to the LakeRipple editor; nothing is posted automatically. Helpful tips may be featured on this page (we'll use your first name only if you give one).
Straight-line distance between lake centers. All Idaho lakes & ponds · All waters in Bruneau