Eighteenmile Creek

Tributary of the Lemhi River

    Eighteenmile Creek in Lemhi County is 30.9 miles in length.

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    Species Observed in Surveys

    Fish Stocking Records

    Date Species Quantity General Size
    2013/05/20 Rainbow Trout - Triploid 508 Catchable (6+ inches)
    1972/06/07 Brook Trout 1,950 Fry (0-3 inches)
    1972/06/07 Cutthroat Trout - Unspecified 6,000 Fry (0-3 inches)
    1971/08/14 Brook Trout 1,080 Fry (0-3 inches)
    1971/06/09 Brook Trout 900 Fry (0-3 inches)
    1971/06/09 Cutthroat Trout - Unspecified 3,000 Fry (0-3 inches)
    1971/06/08 Brook Trout 900 Fry (0-3 inches)
    1971/06/08 Cutthroat Trout - Unspecified 3,000 Fry (0-3 inches)
    1971/06/07 Brook Trout 900 Fry (0-3 inches)
    1970/08/27 Cutthroat Trout - Unspecified 1,800 Fry (0-3 inches)
    1970/08/27 Rainbow Trout 2,100 Fingerling (3-6 inches)
    1970/06/11 Cutthroat Trout - Unspecified 6,000 Fry (0-3 inches)
    1969/07/25 Cutthroat Trout - Unspecified 1,600 Fry (0-3 inches)
    1968/07/22 Cutbow - Cutthroat x Rainbow Trout 2,850 Fry (0-3 inches)
    1968/07/22 Cutbow - Cutthroat x Rainbow Trout - Diploid 2,850 Fry (0-3 inches)
    Source: IDFG Fish Stocking Database.

    Licenses and Tags

    Learn more about IDFG Licenses, Tags & Permits
     

    Fishing Rules, 2025 - 2027

    All Waters Open All Year

    Except as modified in Special Rules
    Fishing is not allowed within the posted upstream and downstream boundary of any fish weir or trap.

    Daily Bag Limits

    The following daily bag limits apply to all waters within each region except as modified in the Special Rules. The possession limit is 3-times the daily bag limit.

    Special Rules

    Lemhi River tributaries
    • Salmon Region general rules apply
    Salmon Region Bag Limits
    Bass (Largemouth and Smallmouth)

    • No bag, length, or possession limits

    Brook Trout

    • Brook Trout limit is 25
    • Harvest allowed during any open season unless otherwise noted under Special Rules - if gear or bait restrictions are listed, they apply when fishing for Brook Trout

    Bull Trout

    • Bull Trout - catch-and-release

    Kokanee

    • Kokanee limit is 25

    Salmon (ocean-run)

    • Spring and summer Chinook Salmon seasons and limits are set by the Idaho Fish and Game Commission and issued in separate brochures
    • Seasons and limits for fall Chinook Salmon and Coho Salmon can be found here
    • Sockeye Salmon fishing is illegal. Defined as ocean-run Oncorhynchus nerka longer than 14 inches in the Salmon River drainage (excluding above Mosquito Flat Dam)
    • Fishing for salmon is prohibited unless a salmon season is specifically opened for that water

    Steelhead (ocean-run)

    • Defined as Rainbow Trout longer than 20 inches in the Salmon River drainage (excluding the Lemhi and Pahsimeroi rivers, lakes and reservoirs, and ponds)
    • Fishing for steelhead is prohibited unless a steelhead season is specifically opened for that water. See fishing regulations for details

    Sturgeon

    • Sturgeon - catch-and-release
    • Sturgeon must not be removed from the water and must be released upon landing
    • Barbless hooks, sliding swivel device to secure a weight, and a lighter test line to secure weight to sliding swivel device are required. See fishing regulations for details

    Tiger Muskie

    • Tiger Muskie limit is 2, none under 40 inches

    Trout includes Lake Trout, Golden Trout, Arctic Grayling, Cutthroat Trout, Rainbow Trout, Sunapee Trout and trout hybrids (e.g. Tiger Trout)

    • Trout limit is 6, all species combined
    • Chinook Salmon and steelhead placed in ponds are counted in the trout bag limit
    • Bull Trout and Brook Trout are listed separately

    Whitefish

    • Whitefish limit is 25
    • Harvest allowed during any open season unless otherwise noted under Special Rules - if gear or bait restrictions are listed, they apply when fishing for whitefish

    Protected Nongame Fish including Pacific Lamprey

    • May not be harvested or possessed

    All Other Fish Species includes bullfrogs and crayfish

    • No bag, length, or possession limits
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