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589-acre lake in Kenora District, Ontario. The lake tops out around 69 ft. Contours on this water are modeled from its actual shoreline and max depth. Good for finding likely water, never for navigation. Species by species, here's what the data says the year looks like.
Forty Mile Lake maps at 588 acres behind 6.5 miles of shoreline — one island included. A middling shoreline index (1.9) gives it some bays to work without being a maze. The shallow band under 15 ft claims about 31% of the surface on the model — that's where the groceries are. Tip to tip the water measures near 1.5 mi with a 1.4-mi widest point. Kenora District claims this one. If the bite dies, Zarn Lake is 2 mi to the southeast.
Early season lake trout use the shallows, holding in 10 to 40 ft. Summer is a 21 to 69 ft game here, winter a 17 to 69 ft one. The chart's best answer is Deep basin — deep basin, 59 ft, prime for summer. Best bite is early morning. Tie on a white tube jig (deep) or a magnum spoon on downrigger and you're in the game.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Main-lake point (17 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 21 to 69 ft chart-limited; documented 50 to 120 ft | dawn | Deep basin (59 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Main-lake point (17 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 17 to 69 ft chart-limited; documented 20 to 80 ft | dawn | Deep basin (59 ft) | White tube jig, Airplane jig |
Spring puts cisco (lake herring) in skinny water — 10 to 40 ft is the zone. Warm water sends them out to 21 to 69 ft; cold water stacks them in 20 to 60 ft. Deep basin is the standout, a deep basin at roughly 59 ft, rated prime for summer cisco (lake herring). Plan around early morning in the warm months. A vertical flutter spoon (small) or a drop-shot micro plastic covers the summer program.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Break off the point (31 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 21 to 69 ft chart-limited; documented 40 to 80 ft | dawn | Deep basin (59 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | open water | Small casting spoon, Inline spinner (silver) |
| Winter | 20 to 60 ft | dawn | Deep basin (59 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
Spring puts yellow perch in skinny water — 3 to 12 ft is the zone. As the season builds they drop to 10 to 30 ft, wintering in 15 to 35 ft. Spring yellow perch concentrate at Shallow bay flat, a prime-rated weed flat around 6 ft. Warm-month bites cluster around early morning. A drop-shot micro plastics or a small spoon tipped with worm covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (6 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (31 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (31 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Break off the point (31 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Spring northern pike on Forty Mile Lake hold shallow, usually 2 to 8 ft. By summer they slide out to 8 to 20 ft, and by winter most fish are in 5 to 15 ft. The chart's best answer is Shallow bay flat — weed flat, 6 ft, prime for spring. Prime time lands in early morning and the evening. The summer box starts with a bucktail or a weedless spoon over cabbage.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (6 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Shallow bay flat (6 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Shallow bay flat (6 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (6 ft) | Tip-ups, Large jigging spoon |
Count 6 structure marks on this chart. The deepest, Deep basin, sits near 59 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 Forty Mile Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Forty Mile Lake is about 69 ft (21 m) deep at its deepest point. The contours here are modeled from the water's real shape and maximum depth, so treat them as a rough guide.
Anglers target lake trout, cisco (lake herring), yellow perch, northern pike on Forty Mile Lake.
Deep basin is the top-rated area: a deep basin in about 59 ft of water that rates prime for lake trout in summer. Open the map above to see every rated spot for each species and season.
For lake trout, 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 Forty Mile 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.
Zarn Lake 2 mi · Split Lake 2 mi · Jorick Lake 4 mi · Kirk Lake 4 mi · Bawden Lake 5 mi · Clamshell Lake 6 mi · Botsford Lake 6 mi · Mullen Lake 6 mi · Hidden Lake 7 mi · Supee Lake 8 mi · Burnt Dam Lake 8 mi · Pepperbell L. 9 mi
See how Forty Mile Lake stacks up: best northern pike lakes in Ontario · best yellow perch lakes in Ontario · best lake trout lakes in Ontario · best cisco (lake herring) lakes in Ontario
More water nearby: Kenora District fishing maps (1173 charts). Browse all Ontario fishing maps. See every water on DepthScout. 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.