Bosworth Lake

2024 Trout Derby

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About two miles south of Granite Falls. Fishing opportunities include stocked Rainbow Trout, resident Coastal Cutthroat Trout, and Largemouth Bass. On August 8th, 2016, the state record Largemouth Bass (12.53 pounds) was caught from Lake Bosworth by Bill Evans of Bothell, underscoring the potential for big bass in western Washington lakes.   

This lake is one of only twelve waters in Snohomish County managed with a seasonal fishing closure. Spring catch rates for trout are highest early in the season and decline as fish are harvested and as warmer water temperatures force trout to seek areas of colder refuge. Fall is often overlooked by anglers, but can be an ideal time as fish that have been growing all summer become more active around the lake with cooler temperatures.

A WDFW access on the northeast corner offers boat launching with limited parking, and a toilet. Gasoline-powered motors are prohibited.

Two-pole fishing is allowed

Shoreline access: Good - WDFW access only

Species you might catch

Lake information

County: Snohomish
Acreage: 102.30 ac.
Elevation: 562 ft.
Center: 48.043358, -121.970741
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Catchable fish plants

Release Location: BOSWORTH LK (SNOH)
Stock Date Species Number Released Number of Fish Per Pound Facility
Apr 16, 2024 Rainbow 2,875 2.5 ARLINGTON HATCHERY
Apr 15, 2024 Rainbow 6,633 2.2 ARLINGTON HATCHERY
Apr 13, 2023 Rainbow 3,263 2.5 ARLINGTON HATCHERY
Apr 11, 2023 Rainbow 6,400 2.5 ARLINGTON HATCHERY
Apr 13, 2022 Rainbow 50 0.5 ARLINGTON HATCHERY
Apr 13, 2022 Rainbow 3,025 2.5 ARLINGTON HATCHERY
Apr 12, 2022 Rainbow 5,492 2.1 ARLINGTON HATCHERY
Apr 12, 2022 Rainbow 1,000 2.5 ARLINGTON HATCHERY
Apr 13, 2021 Rainbow 3,674 2.2 ARLINGTON HATCHERY
Apr 13, 2021 Rainbow 6,384 2.1 ARLINGTON HATCHERY

Fishing prospects calendar

Rainbow trout

Fishing success for Rainbow Trout is generally best in the spring when thousands of fish are stocked statewide, but they can be caught year-round in most waters with a little patience and persistence. Success remains high into June and gradually declines as water temperatures increase and fish move offshore to stay cool. Fish that escaped the spring harvest return to the nearshore areas in the fall as waters cool off. Some waters may also be stocked again in the fall further boosting catch rates.
Chart showing fishing prospects throughout the calendar year

Coastal cutthroat trout (resident)

Fishing is best for Coastal Cutthroat in the spring and fall. There is a summer lull as fish move offshore into deeper waters to escape the summer heat in July and August. Catch is lowest in the late-winter while adults are spawning in tributary streams.
Chart of fishing prospects throughout the calendar year

Largemouth bass

Fishing improves throughout the spring as waters warm and fish move onshore, peaking during the spawn. Summer is a slight lull though dawn/dusk hours can be very good. Catch improves in Fall as waters cool, vegetation begins to die back, and prey becomes more available. Winter is the hardest time because fish are offshore and slow moving.
Chart of fishing prospects throughout the calendar year

Pumpkinseed Sunfish

Pumpkinseed Sunfish are ubiquitous in most lowland lakes and readily caught year-round. Fishing is best in the spring and summer, peaking during the spawn in June. Fish move offshore into deeper waters through the fall as water temperatures cool making it more difficult to target them. Winter is the most difficult season to catch Pumpkinseed, but persistent anglers can find nice-sized schools offshore.
Chart of fishing prospects throughout the calendar year


Bosworth Lake
Photo by WDFW