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378-acre lake in Sudbury District, Ontario. The lake tops out around 80 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. Here's the year, species by species, as the scoring engine sees it.
Traced from the shoreline, St. Leonard Lake runs 380 acres with 6 miles of edge, broken up by 2 islands. The 2.2 development index tells the story — a convoluted bank whose fishable edge far outruns the acreage. 34% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Figure 1.3 mi of water from one end to the other, 1.1 mi at the beam. The water lies in Sudbury District. Closest neighbour on DepthScout: Pleasant Lake, 1 mi southwest of here.
In spring, lake trout run shallow here, mostly 10 to 40 ft. Summer pushes them deeper, 24 to 80 ft, and winter fish settle into 20 to 80 ft. Deep basin is the standout, a deep basin at roughly 69 ft, rated prime for summer lake trout. Time it for early morning. You won't need more than a white tube jig (deep) or a magnum spoon on downrigger most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Break off the point (41 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 24 to 80 ft | dawn | Deep basin (69 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Break off the point (41 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | Deep basin (69 ft) | White tube jig, Airplane jig |
Spring cisco (lake herring) on St. Leonard Lake hold shallow, usually 10 to 40 ft. By summer they slide out to 40 to 80 ft, and by winter most fish are in 20 to 60 ft. The chart's best answer is Deep basin — deep basin, 69 ft, prime for summer. Prime time lands in early morning. The summer box starts with a vertical flutter spoon (small) or a drop-shot micro plastic.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Break off the point (41 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 40 to 80 ft | dawn | Deep basin (69 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 (69 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
When the water first warms, walleye slide up into 4 to 15 ft. Summer is a 15 to 35 ft game here, winter a 20 to 40 ft one. Start at Break off the point. It's a drop-off holding about 41 ft of water and rates prime come fall. The feeding windows run the evening and early morning. Keep a crawler harness on bottom bouncer or a deep crankbait (trolled) rigged through the warm months.
| 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 | Break off the point (41 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Break off the point (41 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Break off the point (41 ft) | Jigging spoon + minnow head, Rattle bait |
When the water first warms, yellow perch slide up into 3 to 12 ft. By summer they slide out to 10 to 30 ft, and by winter most fish are in 15 to 35 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 1 ft that scores prime in spring. In summer the feeding windows fall in early morning. Keep a drop-shot micro plastics or a small spoon tipped with worm rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (1 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Deep basin (69 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 | Deep basin (69 ft) | Tungsten jig + spikes, Rattle spoon (small) |
The spring pattern is a shallow one: smallmouth bass in 3 to 12 ft. As the season builds they drop to 10 to 30 ft, wintering in 20 to 45 ft. Top water on the chart: Break off the point, a drop-off in the 41 ft range, prime in winter. Time it for early morning and the evening. Summer baits: a drop shot (goby/minnow) or a ned rig gets it done.
| 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 | Break off the point (41 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 | Break off the point (41 ft) | Blade bait, Hair jig |
Spring rock bass on St. Leonard Lake hold shallow, usually 2 to 10 ft. By summer they slide out to 5 to 20 ft, and by winter most fish are in 12 to 30 ft. The chart's best answer is Main-lake point — point, 1 ft, prime for summer. Prime time lands in the evening. The summer box starts with a ned rig (small) or a marabou jig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | Main-lake point (1 ft) | 1/16 oz jig + grub, Small inline spinner |
| Summer | 5 to 20 ft | dusk | Main-lake point (1 ft) | Ned rig (small), Marabou jig |
| Fall | 8 to 22 ft | midday | Break off the point (41 ft) | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Deep basin (69 ft) | Tungsten jig + plastic, Small spoon + spike |
St. Leonard Lake also holds burbot (24 to 80 ft in summer). Pick any of them on the map above for rated spots and bait picks.
6 pieces of structure are mapped here — Deep basin, around 69 ft, is the deepest of them.
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 St. Leonard Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
St. Leonard Lake is about 80 ft (24 m) deep at its deepest point. 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.
Anglers target lake trout, cisco (lake herring), walleye, yellow perch, smallmouth bass, rock bass, burbot on St. Leonard Lake.
Deep basin is the top-rated area: a deep basin in about 69 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 St. Leonard 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.
Pleasant Lake 1 mi · Elizabeth Lake 1 mi · Stratton Lake 2 mi · Brazil Lake 2 mi · Nameless Lake 2 mi · Augusta Lake 2 mi · Arts L. 3 mi · Loon Lake 3 mi · Deerhound Lake 3 mi · Porcupine Lake 3 mi · Spring Lake 4 mi · Anderson Lake 4 mi
See how St. Leonard Lake stacks up: best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best yellow perch lakes in Ontario · best lake trout lakes in Ontario
More water nearby: Sudbury District fishing maps (868 charts). Browse all Ontario fishing maps or 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.