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603-acre lake in Thunder Bay District, Ontario. The lake tops out around 27 ft. The depth data here comes from the Ontario MNRF survey of 1975, a decades-old survey (a transect sounding survey). Here's the year, species by species, as the scoring engine sees it.
On the chart, Purdom Lake draws 606 acres inside 16 miles of shoreline, with 54 islands in the mix. A development index of 4.6 means a maze of bays and points: far more casting targets than a round bowl of the same size. 91% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Call it 2.2 mi long by 0.9 mi wide at the broadest reach. You'll find it in Thunder Bay District. Closest neighbour on DepthScout: Mound Lake, 7 mi west of here.
The spring pattern is a shallow one: brook trout in 2 to 15 ft. As the season builds they drop to 8 to 27 ft, wintering in 3 to 20 ft. Top water on the chart: Deep basin, a deep basin in the 25 ft range, prime in summer. Time it for early morning and the evening. Summer baits: a small spoon fished deep or a trolled lake-clear wobbler + worm gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 15 ft | dawn & dusk | Main-lake point (1 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 8 to 27 ft | dawn & dusk | Deep basin (25 ft) | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 2 to 15 ft | midday & dawn | Main-lake point (1 ft) | Small spoon (orange), Spinner |
| Winter | 3 to 20 ft | dawn | Break off the point (1 ft) | Small jigging spoon, Tungsten jig + plastic |
Come spring, look for cisco (lake herring) tight to the bank in 7 to 27 ft. Through summer count on 8 to 27 ft; the winter hold is 8 to 27 ft. If you only fish one area, make it Deep basin: a deep basin around 25 ft that scores prime in spring. Best bite is early morning. A vertical flutter spoon (small) or a drop-shot micro plastic is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 7 to 27 ft | dawn & dusk | Deep basin (25 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 8 to 27 ft | dawn | Deep basin (25 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (1 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 8 to 27 ft | dawn | Deep basin (25 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
Early season yellow perch use the shallows, holding in 3 to 12 ft. Summer is an 8 to 27 ft game here, winter an 8 to 27 ft one. The chart's best answer is Deep basin — deep basin, 25 ft, prime for fall. Best bite is early morning. Tie on a drop-shot micro plastics or a small spoon tipped with worm and you're in the game.
| 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 | 8 to 27 ft | dawn | Deep basin (25 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 8 to 27 ft | midday | Deep basin (25 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 8 to 27 ft | midday & dawn | Deep basin (25 ft) | Tungsten jig + spikes, Rattle spoon (small) |
In spring, smallmouth bass run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 8 to 27 ft before dropping to 8 to 27 ft for winter. Winter smallmouth bass concentrate at Deep basin, a good-rated deep basin around 25 ft. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a drop shot (goby/minnow) or a ned rig most summer days.
| 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 | 8 to 27 ft | dawn & dusk | Break off the 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 | 8 to 27 ft | midday | Deep basin (25 ft) | Blade bait, Hair jig |
Purdom Lake carries 7 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 25 ft down.
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 Purdom Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Purdom Lake is about 27 ft (8 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1975, a decades-old survey (a transect sounding survey).
Anglers target brook trout, cisco (lake herring), yellow perch, smallmouth bass on Purdom Lake.
Deep basin is the top-rated area: a deep basin in about 25 ft of water that rates prime for cisco (lake herring) in spring. Every other rated spot, per species and season, is on the map above.
For brook trout, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Purdom 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.
Mound Lake 7 mi · Deer Lake 7 mi · Frazer Lake 8 mi · Cox Lake 9 mi · Eskwanonwatin Lake 9 mi · Nonwatinose Lake 11 mi · Nonwatin Lake 13 mi · Oskawe Lake 14 mi · Driftstone Lake 14 mi · McKirdy Lake 15 mi · Black Mountain Lake 15 mi · Shamrock Lake 15 mi
See how Purdom Lake stacks up: best smallmouth bass lakes in Ontario · best yellow perch lakes in Ontario · best brook trout lakes in Ontario · best cisco (lake herring) lakes in Ontario
More water nearby: Thunder Bay District fishing maps (662 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.