Warm temperatures and a dry spring and summer caused water levels to drop sharply across southeastern Idaho. American Falls Reservoir hit just 3% of its usual capacity this fall. With so little water, rainbow trout—normally famed for their rapid growth and trophy status in American Falls—now face rising temperatures and dwindling oxygen. Many trout are forced to flee down river in search of livable water.
Regional Fisheries Manager Patrick Kennedy says water availability is key to whether fish populations and larger fish thrive in the coming years.
This year, aggressive water releases and repair work at Minidoka Dam dropped Snake River flows near record lows—just 2% of summer’s peak. Winter is already a tough season for trout, and this lack of habitat may impact other reservoirs as well. Until conditions improve, anglers should prepare for challenging fishing and smaller catches in southeastern Idaho’s popular reservoirs.
