Lake depth chart
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82-acre lake in Cochrane District, Ontario. The lake tops out around 75 ft. Depth here is modeled from the true shoreline and max depth rather than surveyed; use it to plan, not to navigate. Below is the species-by-species picture, pulled from the same data the map uses.
The outline encloses 83 acres, worked by 3.2 miles of shoreline. With a shoreline index of 2.5, this water is all arms and coves — edge habitat well beyond its acreage. The shallow band under 15 ft claims about 66% of the surface on the model — that's where the groceries are. The basin spans about 0.9 mi end to end and 0.4 mi across at its widest. It sits in Cochrane District. Jeannie Lake sits 0 mi southwest — the closest neighbouring chart.
When the water first warms, lake trout slide up into 10 to 40 ft. By summer they slide out to 23 to 75 ft, and by winter most fish are in 19 to 75 ft. If you only fish one area, make it Deep basin: a deep basin around 64 ft that scores prime in summer. In summer the feeding windows fall in early morning. Keep a white tube jig (deep) or a magnum spoon on downrigger rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Main-lake point (19 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 23 to 75 ft | dawn | Deep basin (64 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Main-lake point (19 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 19 to 75 ft | dawn | Deep basin (64 ft) | White tube jig, Airplane jig |
In spring, walleye run shallow here, mostly 4 to 15 ft. Midsummer fish sit out in 15 to 35 ft before dropping to 20 to 40 ft for winter. Fall walleye concentrate at Break off the point, a prime-rated drop-off around 34 ft. Fish it in the evening and early morning and you'll meet the bite. You won't need more than a crawler harness on bottom bouncer or a deep crankbait (trolled) most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (19 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Break off the point (34 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Break off the point (34 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Break off the point (34 ft) | Jigging spoon + minnow head, Rattle bait |
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 Shallow bay flat, a weed flat in about 6 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 | Shallow bay flat (6 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (34 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (34 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Break off the point (34 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 6 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 (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 |
When the water first warms, smallmouth bass slide up into 3 to 12 ft. Summer is a 10 to 30 ft game here, winter a 20 to 45 ft one. Start at Main-lake point. It's a point holding about 19 ft of water and rates prime come fall. The feeding windows run early morning and the evening. Keep a drop shot (goby/minnow) or a ned rig rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | open water | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (19 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (19 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Break off the point (34 ft) | Blade bait, Hair jig |
Structure-wise the chart holds 6 features, led in depth by Deep basin at roughly 64 ft.
Access data: Geospatial Ontario - Fishing Access Points. Confirm conditions and fees locally before you launch.
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 Mary Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Mary Lake is about 75 ft (23 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, walleye, yellow perch, northern pike, smallmouth bass on Mary Lake.
Deep basin is the top-rated area: a deep basin in about 64 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 Mary 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.
Jeannie Lake 0 mi · Alpine Lake 1 mi · Tom Lake 1 mi · Martin L. 2 mi · Cole Lake 5 mi · Mann L. 3 6 mi · Mann L. 2 7 mi · Mann L. 4 7 mi · Nellie Lake 7 mi · Fletchers Lake 7 mi · Little Lake 7 mi · Devonshire Lake 8 mi
See how Mary Lake stacks up: best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch lakes in Ontario
More water nearby: Cochrane District fishing maps (673 charts). Browse all Ontario fishing maps or 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.