Shared by DepthScout anglers. Exact spots stay private, always.
2,131-acre lake in Muskoka District Municipality, Ontario. The lake tops out around 30 ft. The depth data here comes from the Ontario MNRF survey of 1972, a decades-old survey (a transect sounding survey). Species by species, here's what the data says the year looks like.
Three Mile Lake maps at 2,140 acres behind 25 miles of shoreline — 5 islands included. An index of 3.9 puts the bank firmly in maze territory: point after pocket after cove, every one a casting target. Roughly 80% of the water is 15 ft or less, the band where the food chain lives. End to end it runs roughly 4.7 mi, about 2.6 mi across. Muskoka District Municipality claims this one. If the bite dies, Cowan Lake is 2 mi to the southwest.
Spring puts cisco (lake herring) in skinny water — 8 to 30 ft is the zone. Summer fish stay in 9 to 30 ft, and winter fish hold in 9 to 30 ft. Deep basin is the standout, a deep basin at roughly 30 ft, rated prime for spring 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.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 30 ft | dawn & dusk | Deep basin (30 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 9 to 30 ft | dawn | Deep basin (30 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (3 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 9 to 30 ft | dawn | Deep basin (30 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
Start shallow in spring: walleye sit in 4 to 15 ft that time of year. Summer pushes them deeper, 9 to 30 ft, and winter fish settle into 9 to 30 ft. The spot to know is Deep basin, a deep basin in about 30 ft of water that rates prime for walleye in winter. Warm-month bites cluster around the evening and early morning. Throw a crawler harness on bottom bouncer or a deep crankbait (trolled) until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (8 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 9 to 30 ft | dusk & dawn | Main-lake point (8 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 9 to 30 ft | dusk & night | Main-lake point (8 ft) | Jigging rap, Jig + big minnow |
| Winter | 9 to 30 ft | dusk & dawn | Deep basin (30 ft) | Jigging spoon + minnow head, Rattle bait |
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 9 to 30 ft. Spring yellow perch concentrate at Back-bay flat, a prime-rated weed flat around 3 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 | Back-bay flat (3 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Deep basin (30 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 9 to 30 ft | midday | Deep basin (30 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 9 to 30 ft | midday & dawn | Deep basin (30 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Spring smallmouth bass on Three Mile Lake hold shallow, usually 3 to 12 ft. By summer they slide out to 10 to 30 ft, and by winter most fish are in 9 to 30 ft. The chart's best answer is Main-lake point — point, 8 ft, prime for fall. Prime time lands in early morning and the evening. The summer box starts with a drop shot (goby/minnow) or a ned rig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Main-lake point (8 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (8 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (8 ft) | Jerkbait, Blade bait |
| Winter | 9 to 30 ft | midday | Break off the point (3 ft) | Blade bait, Hair jig |
Early season largemouth bass use the shallows, holding in 2 to 10 ft. Expect a summer slide to 8 to 20 ft, then a winter hold in 9 to 30 ft. Put Shallow bay flat first on the milk run — a weed flat near 2 ft that grades prime for spring. In summer the feeding windows fall in early morning and the evening. Tie on a texas-rigged 10" worm or a deep-diving crankbait and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | dawn & dusk | Shallow bay flat (2 ft) | Spinnerbait, Chatterbait |
| Summer | 8 to 20 ft | dawn & dusk | Main-lake point (8 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Main-lake point (8 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 9 to 30 ft | midday | Deep basin (30 ft) | Blade bait, Jigging spoon |
Spring puts rock bass in skinny water — 2 to 10 ft is the zone. Warm water sends them out to 5 to 20 ft; cold water stacks them in 12 to 30 ft. Main-lake point is the standout, a point at roughly 8 ft, rated prime for summer rock bass. Plan around the evening in the warm months. A ned rig (small) or a marabou jig covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | Main-lake point (8 ft) | 1/16 oz jig + grub, Small inline spinner |
| Summer | 5 to 20 ft | dusk | Main-lake point (8 ft) | Ned rig (small), Marabou jig |
| Fall | 8 to 22 ft | midday | Main-lake point (8 ft) | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Deep basin (30 ft) | Tungsten jig + plastic, Small spoon + spike |
Three Mile Lake also holds pumpkinseed (2 to 10 ft in summer), brown bullhead (3 to 12 ft in summer). Pick any of them on the map above for rated spots and bait picks.
The chart marks 7 structure features on Three Mile Lake; the deepest is Deep basin at about 30 ft.
Access data: Land Information Ontario — Fishing Access Point. 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 Three Mile Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Three Mile Lake is about 30 ft (9 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1972, a decades-old survey (a transect sounding survey).
Anglers target cisco (lake herring), walleye, yellow perch, smallmouth bass, largemouth bass, rock bass, pumpkinseed, brown bullhead on Three Mile Lake.
Deep basin is the top-rated area: a deep basin in about 30 ft of water that rates prime for cisco (lake herring) in spring. Scroll up to the map for the complete spot list by species and season.
For cisco (lake herring), 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 Three 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.
Cowan Lake 2 mi · Nutt Lake 2 mi · Cherry Island L. 3 mi · Camel Lake 3 mi · High Lake 4 mi · Young Lake 4 mi · Skeleton Lake 5 mi · Kling Biels L. 5 mi · Little Long Lake 5 mi · Barnes Lake 6 mi · Brandy Lake 6 mi · Longs Lake 6 mi
See how Three Mile Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best yellow perch lakes in Ontario
More water nearby: Muskoka District Municipality fishing maps (276 charts). Browse all Ontario fishing maps or see every water on DepthScout. Bathymetry credit: state fisheries survey programs. 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.