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Big Trinity Lake

Idaho City, Idaho — Elmore County.

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26Surface acres

Surface area: The USGS National Hydrography Dataset outline (NHD Permanent ID 55021735).

Location & fast facts

Where Big Trinity Lake is in Idaho

The red circle marks Big Trinity Lake.

Fast facts

About Big Trinity Lake

  • County: Elmore
  • Nearest city: Idaho City (about 21.7 mi from the lake)
  • Mapped as: Lake or pond (USGS National Hydrography Dataset)
  • Distance: about 39 mi from Boise and 88 mi from Twin Falls, straight-line (not driving distance)

Towns and counties: U.S. Census Bureau boundaries overlaid on the USGS lake outline (Idaho: incorporated places touching the lake, otherwise the nearest one).

Fishing in Idaho

Official IDFG pages. Rules and fees change; check before you go.

Good for & watch for

Good for

  • Fishing. Rainbow trout and Cutthroat trout
  • Camping. 14 campgrounds within 15 mi (list)

Watch for

    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.

    Official stocking data (Idaho Fish and Game)

    Stocked by the state: Cutthroat trout, Rainbow trout (2015–2026, 12 years; 71,171 fish in all, fry included)

    Source: Idaho Department of Fish and Game, Idaho Fishing Planner stocking records (releases into Big Trinity Lake, Elmore County, since 2015). These are stocking records, not a full fish survey; other species also live here.

    Lake map

    Big Trinity Lake shoreline

    0.1 mileN

    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 55021735), 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.

    Campgrounds near Big Trinity Lake

    We found 14 campgrounds and RV parks within 15 miles of Big Trinity Lake, 1 of them within 5 miles. Distances are straight-line from the nearest point on the shoreline, so driving distance is longer.

    8 more within 15 miles

    All campgrounds & RV parks in Idaho

    Green tent icons on the lake map mark campgrounds near the shore, and the interactive map shows the closest 12. Amenities are listed only where a source records them; call or check the campground's website before you go, since seasons and rates change every year.

    Campground data: Recreation.gov (RIDB) · OpenStreetMap contributors (ODbL). Pulled Oct 12, 2026.

    Nearest airports

    The closest airport with scheduled passenger flights to Big Trinity Lake, plus larger airports within about 150 miles:

    Car rental links go to our partner Discover Cars; LakeRipple may earn a commission at no extra cost to you. Affiliate disclosure.

    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.

    Conditions right now

    Air temperature & conditions (nearest NWS station)Loading…
    Fetching the latest National Weather Service observation…

    Live from the National Weather Service API for the lake's coordinates (43.6239, -115.4288). The nearest station may be several miles away. NWS forecast for Big Trinity Lake. No live water-temperature sensor is shown because we haven't found a public one for this lake.

    Sun, moon & best fishing times

    Sun & moon at Big Trinity Lake

    Best fishing times

    Major periodMinor periodDaylight

      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.

      Contact & official info

      Questions about Big Trinity Lake

      How big is Big Trinity Lake?

      Big Trinity Lake covers about 26 acres in Idaho City, Idaho (Elmore County).

      What fish are in Big Trinity Lake?

      IDFG fish stocking records lists Rainbow trout and Cutthroat trout.

      Are there campgrounds near Big Trinity Lake?

      Yes. We list 14 campgrounds and RV parks within 15 miles, 1 of them within 5 miles.

      What towns are on Big Trinity Lake?

      Big Trinity Lake touches Idaho City in Elmore County, Idaho.

      Share a tip or fishing report

      Know Big Trinity Lake? 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).

      Lakes & ponds nearby

      Straight-line distance between lake centers. All Idaho lakes & ponds · All waters in Idaho City