Grasmere Reservoir in Owyhee County: How and When to Fish It

• Overview

  Owyhee County in Idaho is where Grasmere Reservoir sits. The surface lies 5,194 feet up. Around 29 acres of surface means several distinct areas to work. Around 1.2 miles of margin, front to back. Nearest town is Glenns Ferry, 51 miles off. For a city, Boise is 88 miles off. It sits well inside the county, so one set of rules covers it.

• Where to Fish on Grasmere Reservoir

  Depth is not on record here, which means reading the ground instead. Draw-down through summer strips the margins, so follow the water out. Inflow corners move water, and moving water gathers fish. Species logged across Owyhee County include rainbow trout, great basin cutthroat trout and smallmouth bass. Records at county level tell you what is around, not what is stocked here. Grasmere Reservoir fishes better once you know its edges.

• Seasonal Patterns

  Averages here run 68°F at the top of summer and 29°F at the bottom of winter. Seasons here are moderate, and the fishing runs most of the year. Some winters give nothing at all, so plan for open water. March through May is the strongest run, with October and November a second stretch. It sets the rhythm of the year at Grasmere Reservoir.

• Tackle & Baits

  The access position is unclear from public sources. Nothing is listed nearby for parking or launching a boat. Bass water: a Texas-rigged worm near cover, a spinnerbait when you need to cover ground. Parking is often the real limit rather than the bank itself. Check whether bait restrictions apply before you buy any. Rattlesnake Reservoir at 7 miles is the sensible second choice. For Grasmere Reservoir, the notice at the access point is the final word.