Lake depth chart
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475-acre lake in Thunder Bay District, Ontario. The lake tops out around 91 ft. Depth here is modeled from the true shoreline and max depth rather than surveyed; use it to plan, not to navigate. The rest of this page walks each species through its year, using the map's own scoring.
The outline encloses 474 acres, worked by 7.9 miles of shoreline. A development index of 2.6 means a maze of bays and points: far more casting targets than a round bowl of the same size. About 41% of the surface sits shallower than 15 ft on the modeled chart — that's the weed-and-bait zone. Call it 1.5 mi long by 1.3 mi wide at the broadest reach. It sits in Thunder Bay District. If the bite dies, Cibber L. is 4 mi to the northeast.
Spring lake trout on North Mawn L. hold shallow, usually 10 to 40 ft. By summer they slide out to 27 to 91 ft, and by winter most fish are in 20 to 80 ft. The chart's best answer is Deep basin — deep basin, 77 ft, prime for summer. Prime time lands in early morning. The summer box starts with a white tube jig (deep) or a magnum spoon on downrigger.
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 (23 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 27 to 91 ft chart-limited; documented 50 to 120 ft | dawn | Deep basin (77 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Main-lake point (23 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | Deep basin (77 ft) | White tube jig, Airplane jig |
In spring, lake whitefish run shallow here, mostly 15 to 45 ft. Summer pushes them deeper, 40 to 90 ft, and winter fish settle into 25 to 70 ft. Deep basin is the standout, a deep basin at roughly 77 ft, rated prime for summer lake whitefish. Time it for early morning. You won't need more than a blade bait vertical or a small jigging spoon most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 15 to 45 ft | midday & dawn | Break off the point (41 ft) | Small jig + waxworm, Blade bait (small) |
| Summer | 40 to 90 ft | dawn | Deep basin (77 ft) | Blade bait vertical, Small jigging spoon |
| Fall | 8 to 30 ft | dusk | Main-lake point (23 ft) | Small spoon (gold), Jig + plastic larva |
| Winter | 25 to 70 ft | midday & dawn | Deep basin (77 ft) | Jigging spoon + bead chain, Tungsten jig + waxie |
In spring, yellow perch run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 15 to 35 ft for winter. Spring yellow perch concentrate at Shallow bay flat, a prime-rated weed flat around 6 ft. Fish it in early morning and you'll meet the bite. You won't need more than a drop-shot micro plastics or a small spoon tipped with worm most summer days.
| 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 | Shallow bay flat (6 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (41 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | open water | Tungsten jig + spikes, Rattle spoon (small) |
Early season northern pike use the shallows, holding in 2 to 8 ft. Summer is an 8 to 20 ft game here, winter a 5 to 15 ft one. The chart's best answer is Shallow bay flat — weed flat, 6 ft, prime for spring. Best bite is early morning and the evening. Tie on a bucktail or a weedless spoon over cabbage and you're in the game.
| 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 |
North Mawn L. carries 6 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 77 ft down.
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 North Mawn L. specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
North Mawn L. is about 91 ft (28 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, lake whitefish, yellow perch, northern pike on North Mawn L..
Deep basin is the top-rated area: a deep basin in about 77 ft of water that rates prime for lake trout in summer. The interactive chart above rates every 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 North Mawn L. 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.
Cibber L. 4 mi · Drop Off Lake 5 mi · Twining L. 7 mi · Little Metionga Lake 7 mi · Aylsworth L. 8 mi · Brightsand Lake 9 mi · Metionga L. 10 mi · Empire Lake 10 mi · Weaver Lake 11 mi · Pakashkan Lake 13 mi · Wawang Lake 14 mi · Loganberry Lake 17 mi
See how North Mawn L. stacks up: best northern pike lakes in Ontario · best yellow perch lakes in Ontario · best lake trout lakes in Ontario · best lake whitefish lakes in Ontario
More water nearby: Thunder Bay District fishing maps (662 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.