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2,609-acre lake in Muskoka District Municipality, Ontario. The lake tops out around 190 ft. The depth chart comes from Ontario Ministry of Natural Resources and Forestry bathymetric survey data, so the contours are survey-derived rather than computer-modeled. The depth data here comes from the Ontario MNRF survey of 2003 (an MNRF lake survey). What the data behind the map says about each species, season by season:
Traced from the shoreline, Mary Lake runs 2,620 acres with 14.5 miles of edge, with 7 islands in the mix. The shoreline is moderately structured (index 2) — enough points and pockets to pattern. The shallow band under 15 ft claims about 13% of the surface — that's where the groceries are. End to end it runs roughly 4.2 mi, about 1.7 mi across. The water lies in Muskoka District Municipality. Closest neighbour on DepthScout: Penfold Lake, 2 mi northwest of here.
These fish are listed in an exact-water agency record as forage or ecological context. They are not target-species profiles and do not affect DepthScout's Prime, Good, or Fair spot ratings.
Official Ontario MNRF Fish ON-Line record. The listing documents source-recorded presence, not present abundance or guaranteed catchability.
Spring puts lake trout in skinny water — 10 to 40 ft is the zone. As the season builds they drop to 50 to 120 ft, wintering in 20 to 80 ft. Winter lake trout concentrate at Sharp break, a prime-rated drop-off around 56 ft. Warm-month bites cluster around early morning. A white tube jig (deep) or a magnum spoon on downrigger covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Main-lake point (1 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 50 to 120 ft | dawn | Sharp break (56 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Main-lake point (1 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | Sharp break (56 ft) | White tube jig, Airplane jig |
Early season lake whitefish use the shallows, holding in 15 to 45 ft. Expect a summer slide to 40 to 90 ft, then a winter hold in 25 to 70 ft. Put Sharp break first on the milk run — a drop-off near 56 ft that grades prime for summer. In summer the feeding windows fall in early morning. Tie on a blade bait vertical or a small jigging spoon and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 15 to 45 ft | midday & dawn | Feeding flat (16 ft) | Small jig + waxworm, Blade bait (small) |
| Summer | 40 to 90 ft | dawn | Sharp break (56 ft) | Blade bait vertical, Small jigging spoon |
| Fall | 8 to 30 ft | dusk | open water | Small spoon (gold), Jig + plastic larva |
| Winter | 25 to 70 ft | midday & dawn | Sharp break (56 ft) | Jigging spoon + bead chain, Tungsten jig + waxie |
Come spring, look for walleye tight to the bank in 4 to 15 ft. They move out to 15 to 35 ft in summer and finish the year down in 20 to 40 ft. If you only fish one area, make it Feeding flat: a feeding flat around 16 ft that scores good in summer. Best bite is the evening and early morning. A crawler harness on bottom bouncer or a deep crankbait (trolled) is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (1 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Feeding flat (16 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Main-lake point (1 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | open water | Jigging spoon + minnow head, Rattle bait |
Come spring, look for yellow perch tight to the bank in 3 to 12 ft. Expect a summer slide to 10 to 30 ft, then a winter hold in 15 to 35 ft. Start at Feeding flat. It's a feeding flat holding about 8 ft of water and rates prime come spring. Prime time lands in early morning. A drop-shot micro plastics or a small spoon tipped with worm is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Feeding flat (8 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Feeding flat (16 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | open water | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Feeding flat (16 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Start shallow in spring: northern pike sit in 2 to 8 ft that time of year. Summer pushes them deeper, 8 to 20 ft, and winter fish settle into 5 to 15 ft. The spot to know is Feeding flat, a feeding flat in about 8 ft of water that rates prime for northern pike in spring. Warm-month bites cluster around early morning and the evening. Throw a bucktail or a weedless spoon over cabbage until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Feeding flat (8 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Feeding flat (16 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Feeding flat (16 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Feeding flat (8 ft) | Tip-ups, Large jigging spoon |
Start shallow in spring: smallmouth bass sit in 3 to 12 ft that time of year. Summer pushes them deeper, 10 to 30 ft, and winter fish settle into 20 to 45 ft. The spot to know is Main-lake point, a point in about 1 ft of water that rates good for smallmouth bass in spring. Warm-month bites cluster around early morning and the evening. Throw a drop shot (goby/minnow) or a ned rig until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Main-lake point (1 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (1 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (1 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Sharp break (56 ft) | Blade bait, Hair jig |
Mary Lake also holds largemouth bass (8 to 20 ft in summer), rock bass (5 to 20 ft in summer), crappie (10 to 25 ft in summer), pumpkinseed (2 to 10 ft in summer), brown bullhead (3 to 12 ft in summer), burbot (50 to 120 ft in summer), rainbow smelt (25 to 80 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Structure-wise the chart holds 12 features, led in depth by Deep basin at roughly 190 ft.
Access data: Geospatial Ontario - Fishing Access Points; Government of Ontario - MNR Unpatented Crown Land Shoreline; Government of Ontario - MNR Unpatented Crown Land Shoreline. 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 190 ft (58 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 2003 (an MNRF lake survey).
Anglers target lake trout, lake whitefish, walleye, yellow perch, northern pike, smallmouth bass, largemouth bass, rock bass, crappie, pumpkinseed, brown bullhead, burbot, rainbow smelt on Mary Lake.
Sharp break is the top-rated area: a drop-off in about 56 ft of water that rates prime for lake trout in winter. Every other rated spot, per species and season, is on the map above.
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.
Penfold Lake 2 mi · Clearwater Lake 3 mi · Lena Lake 3 mi · Chub Lake 4 mi · Lynx Lake 4 mi · Devine Lake 4 mi · Fleming Lake 4 mi · Rose Lake 5 mi · Fawn Lake 5 mi · Mainhood Lake 5 mi · Tongua Lake 6 mi · Longs Lake 6 mi
See how Mary Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best northern pike lakes in Ontario
More water nearby: Muskoka District Municipality fishing maps (276 charts). Browse all Ontario fishing maps. See every water on DepthScout. Bathymetry: published agency survey data. 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.