Sign inSign up free Sign inSign up free Sign inSign up freeLake depth chart
Today's read
Shared by DepthScout anglers. Exact spots stay private, always.
66-acre lake in Muskoka District Municipality, Ontario. The lake tops out around 40 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 1972, a decades-old survey (an MNRF lake survey). Species by species, here's what the data says the year looks like.
Traced from the shoreline, Cooper Lake runs 67 acres with 2 miles of edge, broken up by an island. The shoreline is moderately structured (index 1.8) — enough points and pockets to pattern. Littoral water — the productive band under ~15 ft — makes up 71% of this chart. Call it 0.6 mi long by 0.4 mi wide at the broadest reach. The water lies in Muskoka District Municipality. The nearest mapped water is Wilson Lake, 2 mi to the southeast.
Early season cisco (lake herring) use the shallows, holding in 10 to 40 ft. Even in summer they hold at 12 to 40 ft; winter keeps them in 12 to 40 ft. Put Deep basin first on the milk run — a deep basin near 40 ft that grades prime for spring. In summer the feeding windows fall in early morning. Tie on a vertical flutter spoon (small) or a drop-shot micro plastic and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Deep basin (40 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 12 to 40 ft | dawn | Deep basin (40 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (20 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 12 to 40 ft | dawn | Deep basin (40 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
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 Break off the point. It's a drop-off holding about 20 ft of water and rates prime come summer. 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 | Shallow bay flat (1 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (20 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (20 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Deep basin (40 ft) | Tungsten jig + spikes, Rattle spoon (small) |
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 12 to 40 ft. The spot to know is Break off the point, a drop-off in about 20 ft of water that rates prime for smallmouth bass in winter. 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 | Break off the point (20 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Break off the point (20 ft) | Jerkbait, Blade bait |
| Winter | 12 to 40 ft | midday | Break off the point (20 ft) | Blade bait, Hair jig |
Early season pumpkinseed use the shallows, holding in 1 to 8 ft. Expect a summer slide to 2 to 10 ft, then a winter hold in 6 to 18 ft. Put Shallow bay flat first on the milk run — a weed flat near 1 ft that grades prime for spring. In summer the feeding windows fall in the evening and early morning. Tie on a micro tube or a sponge spider (fly) and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 1 to 8 ft | midday & dusk | Shallow bay flat (1 ft) | Micro jig under a float, Tiny beetle-spin |
| Summer | 2 to 10 ft | dusk & dawn | Shallow bay flat (1 ft) | Micro tube, Sponge spider (fly) |
| Fall | 4 to 14 ft | dusk & dawn | Shallow bay flat (1 ft) | Micro jig + waxworm, Small spoon tipped |
| Winter | 6 to 18 ft | dawn | Shallow bay flat (1 ft) | Tungsten ice jig + plastic, Tiny spoon |
In spring, brown bullhead run shallow here, mostly 2 to 8 ft. Summer pushes them deeper, 3 to 12 ft, and winter fish settle into 10 to 25 ft. Shallow bay flat is the standout, a weed flat at roughly 1 ft, rated prime for spring brown bullhead. Time it for after dark and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | dusk & night | Shallow bay flat (1 ft) | |
| Summer | 3 to 12 ft | night & dusk | Shallow bay flat (1 ft) | |
| Fall | 5 to 15 ft | dusk | open water | |
| Winter | 10 to 25 ft | midday | Deep basin (40 ft) |
The chart marks 6 structure features on Cooper Lake; the deepest is Deep basin at about 40 ft.
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 Cooper Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Cooper Lake is about 40 ft (12 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1972, a decades-old survey (an MNRF lake survey).
Anglers target cisco (lake herring), yellow perch, smallmouth bass, pumpkinseed, brown bullhead on Cooper Lake.
Deep basin is the top-rated area: a deep basin in about 40 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 Cooper 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.
Wilson Lake 2 mi · Burns Lake 2 mi · Fifteen Mile Lake 2 mi · Sixteen Mile Lake 2 mi · Seventeen Mile Lake 3 mi · Eighteen Mile Lake 3 mi · Solitaire Lake 3 mi · Buck Lake 3 mi · Crotch Lake 4 mi · Hardup Lake 4 mi · Eiler Lake 4 mi · Eastell Lake 4 mi
See how Cooper Lake stacks up: best smallmouth bass lakes in Ontario · best yellow perch lakes in Ontario · best cisco (lake herring) lakes in Ontario · best pumpkinseed 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: 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.