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609-acre lake in Thunder Bay District, Ontario. The lake tops out around 120 ft. The depth data here comes from a transect sounding survey by the Ontario MNRF. Below is the species-by-species picture, pulled from the same data the map uses.
The drawn water covers 611 acres wrapped in 10 miles of bank. An index of 2.9 puts the bank firmly in maze territory: point after pocket after cove, every one a casting target. The shallow band under 15 ft claims about 51% of the surface — that's where the groceries are. Tip to tip the water measures near 3.6 mi with a 0.7-mi widest point. It sits in Thunder Bay District. Kassagimini Lake sits 7 mi northwest — the closest neighbouring chart.
The spring pattern is a shallow one: yellow perch in 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 15 to 35 ft for winter. The spot to know is Back-bay flat, a weed flat in about 7 ft of water that rates prime for yellow perch in spring. Plan around early morning in the warm months. Summer baits: a drop-shot micro plastics or a small spoon tipped with worm gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Back-bay flat (7 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (6 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (6 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Deep basin (119 ft) | Tungsten jig + spikes, Rattle spoon (small) |
When the water first warms, northern pike slide up into 2 to 8 ft. Summer is an 8 to 20 ft game here, winter a 5 to 15 ft one. Start at Shallow bay flat. It's a weed flat holding about 2 ft of water and rates prime come spring. The feeding windows run early morning and the evening. Keep a bucktail or a weedless spoon over cabbage rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (2 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Back-bay flat (7 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Back-bay flat (7 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Back-bay flat (7 ft) | Tip-ups, Large jigging spoon |
The chart marks 6 structure features on Slim Jim Lake; the deepest is Deep basin at about 119 ft.
Season dates, license requirements, and size and bag limits for Ontario waters are set by the Ontario fishing regulations (FMZ summary) — and special regulations can apply to Slim Jim Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Slim Jim Lake is about 120 ft (37 m) deep at its deepest point. The depth data here comes from a transect sounding survey by the Ontario MNRF.
Anglers target yellow perch, northern pike on Slim Jim Lake.
Back-bay flat is the top-rated area: a weed flat in about 7 ft of water that rates prime for yellow perch in spring. Scroll up to the map for the complete spot list by species and season.
For yellow perch, the summer bite is best in early morning. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Slim Jim Lake is regulated by the Ontario fishing regulations (FMZ summary). Check the official Ontario regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Kassagimini Lake 7 mi · Batise Lake 9 mi · Chowder Lake 10 mi · Peanut Lake 10 mi · Flynne Lake 10 mi · Charon Lake 11 mi · Klotz Lake 12 mi · Little Bicknell Lake 13 mi · Bicknell Lake 14 mi · White Otter Lake 15 mi · Flint Lake 17 mi · Pagwachuan Lake 18 mi
See how Slim Jim Lake stacks up: best northern pike lakes in Ontario · best yellow perch lakes in Ontario
More water nearby: Thunder Bay District fishing maps (662 charts). Browse all Ontario 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.