Bosworth Lake Depth Map & Fishing Spots (WA)

Hatch outlook

Callibaetis (Speckled Dun)Active window

Typical here: Aug 15 – Sep 15 · the smaller fall brood

nymphthe hours before the midday emergence — nymphs rise off the weed tops in a vertical zigzag that can take hours — sources split between slow 2–4 inch strips with long pauses and a quicker steady retrieve; carry both speeds
dunmidday, roughly 11am into early afternoon
spinnermid-to-late-morning falls

Trout browse the weed-bed edges knocking nymphs loose, then cruise the flats sipping duns at midday — the marquee western lake mayfly.

The midday emergence puts cruisers over weed flats in under 20 ft: a casting bubble with a #14 Callibaetis nymph retrieved dead-slow with pauses is the honest match. Between hatch hours, small spoons and #1 inline spinners along the weed edges and drop-offs pick off the same fish.

The event happens over weed flats and weed-bed edges in 20 ft of water or less

Chironomids (stillwater midges)Active window

Typical here: May 1 – Oct 31

nymphearly morning, start of the day — fish the bloodworm ON the bottom — 4–6 inches off the mud before the emergence starts
pupathe cool morning hours are prime — as the emergence builds, slide the pupa up to 12–15 inches off bottom under the indicator; a little wind chop does the jigging

Concentrates by DEPTH BAND and mud type, not a fixed spot: roughly 20–25 ft in spring, deeper midsummer, in against the feeder creeks in summer heat, 5–25 ft in fall. Match the band.

This one translates almost perfectly: a slip float with a 1/64–1/100 oz midge-pattern jig set 4–15 inches off bottom over a mud flat, dead-sticked with the chop doing the work. Depth control is everything — no moving lure imitates a hanging pupa; the float rig IS the technique.

The event happens over open mud flats alongside weedlines, channels and basin edges; feeder-creek mouths in summer heat

Water boatman fall flightsActive window

Typical here: Aug 25 – Oct 10 · peaks on crisp, bright fall days after the first cold snap

adultmiddday-ish on calm, sunny fall days — the fishable moment is the splashdown: boatmen dive in headfirst trailing an air bubble and make repeated trips back to the surface — a fly or lure that dives nose-first on the drop imitates exactly this

Takes are seldom subtle — trout ravage boatmen as they hit the water and during their subsurface runs.

Tailor-made for hardware: a small 1/16 oz silver-bellied spoon or jig cast AT the rings of a splashdown sinks headfirst exactly like the natural — twitch-pause it back through the top few feet. On flight days fan-cast the shallow weed margins.

The event happens over near-shore shallows, weed beds and shoal margins on calm sunny fall afternoons

Grasshoppers (east-side summer)Active window

Typical here: Jun 15 – Sep 30

adultall day in high summer, best when afternoon wind knocks bugs onto the water

Pulls fish to the windward grassy banks and edges for months — fish the bank the wind blows ONTO.

The friendliest crossover of the summer: on lakes, drift the windward bank with a bubble-and-foam-hopper — the bubble's splash doesn't hurt a hopper presentation. On rivers, the same rig dead-drifted along the undercut grass banks, or small gold spinners under the banks between rises.

The event happens over grassy banks, undercut edges and windward shorelines

Next on this water

Damselfly migration · forageMay 15 – Jul 31 · in ~9 months

Recommendations come from depth structure and seasonal species behavior. Treat them as a starting point, not a guarantee. Contours here are interpolated from real agency depth surveys (state DNR / USACE). Never use for navigation. Always check local regulations.

Loading depth chart…

Recent catches at Bosworth Lake

Shared by DepthScout anglers. Exact spots stay private, always.

No shared catches here yet — be the first.Log a catch from the map above and share it to put Bosworth Lake on the board.

Fishing Bosworth Lake: what the data says

93-acre lake near Lake Bosworth. The lake tops out around 79 ft. The depth chart is built from real state fisheries GPS surveys, so the humps, channels and drop-offs you see are measured, not guessed. The rest of this page walks each species through its year, using the map's own scoring.

On the chart, Bosworth Lake draws 93 acres inside 1.7 miles of shoreline. A shoreline index of 1.2 says round and simple: fish relate to depth changes here, not shoreline features. About 19% of the surface sits shallower than 15 ft — that's the weed-and-bait zone. The basin spans about 0.7 mi end to end and 0.3 mi across at its widest. The water lies in Snohomish County. For a second option, Lake Roesiger lies 5 mi southeast.

Rainbow Trout fishing at Bosworth Lake

Spring puts rainbow trout in skinny water — 5 to 20 ft is the zone. Warm water sends them out to 8 to 30 ft; cold water stacks them in 8 to 40 ft. Break off the point is the standout, a drop-off at roughly 33 ft, rated prime for winter rainbow trout. Plan around early morning and the evening in the warm months. A dodger + spoon (deep troll) or a flutter spoon covers the summer program.

Season	Depth	Best window	Start at	Go-to baits
Spring	5 to 20 ft	dawn & dusk	Main-lake point (6 ft)	Inline spinner (silver), Small spoon
Summer	8 to 30 ft	dawn & dusk	Break off the point (33 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	10 to 35 ft	dawn & dusk	Break off the point (33 ft)	Casting spoon, Jerkbait over shoals
Winter	8 to 40 ft	dawn	Break off the point (33 ft)	Jigging spoon, Tube jig (white)

Notable structure

6 pieces of structure are mapped here — Deep basin, around 78 ft, is the deepest of them.

Deep basin: deep basin, around 78 ft
Break off the point: drop-off, around 33 ft
Shallow bay flat: feeding flat, around 16 ft
Back-bay flat: feeding flat, around 8 ft
Secondary point: point, around 7 ft
Main-lake point: point, around 6 ft

Public access & boat ramps

Bosworth Lake — ramp (concrete)

Access data: Washington WDFW — Water Access Sites. Confirm conditions and fees locally before you launch.

Bosworth Lake stocking report

Date	Species	Count	Size
Apr 16	Rainbow trout	2,000	—
Apr 14	Rainbow trout	3,000	—
Apr 13	Rainbow trout	3,600	—

Source: WDFW fish-stocking reports, retrieved 2026-08-18.

Bosworth Lake fishing regulations

Season dates, license requirements, and size and bag limits for Washington waters are set by the Washington Department of Fish and Wildlife — and special regulations can apply to Bosworth Lake specifically, so confirm the current rules before you fish.

Check the official Washington fishing regulations →

Common questions

How deep is Bosworth Lake?

Bosworth Lake is about 79 ft (24 m) deep at its deepest point. The depth chart here comes from real state fisheries GPS surveys, so the contours reflect measured depths.

What fish are in Bosworth Lake?

Anglers target rainbow trout on Bosworth Lake.

Where is the best fishing spot on Bosworth Lake?

Break off the point is the top-rated area: a drop-off in about 33 ft of water that rates prime for rainbow trout in winter. The interactive chart above rates every spot for each species and season.

When is the best time to fish Bosworth Lake?

For rainbow trout, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.

Is Bosworth Lake stocked with fish?

Yes — per WDFW fish-stocking reports records, Bosworth Lake was most recently stocked Apr 16 with 2,000 rainbow trout. The full stocking history is listed above.

What are the fishing regulations for Bosworth Lake?

Fishing on Bosworth Lake is regulated by the Washington Department of Fish and Wildlife. Check the official Washington regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.

Nearby waters

Lake Roesiger 5 mi · Lake Cassidy 6 mi · Lake Stevens 6 mi · Flowing Lake 7 mi · Panther Lake 7 mi · Storm Lake 7 mi · Lake Cochran 9 mi · Blackmans Lake 10 mi · Chain Lake 10 mi · Wagner Lake 11 mi · Riley Lake 14 mi · Lake Loma 14 mi

See how Bosworth Lake stacks up: best rainbow trout lakes in Washington

More water nearby: Snohomish County fishing maps (28 charts). Browse all Washington fishing maps or see every water on DepthScout. Bathymetry credit: state fisheries survey programs. How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.