Sign inSign up free Sign inSign up free Sign inSign up freeLake depth chart
Today's read
Recent public catches load as you reach this section.
1,072-acre lake in Thunder Bay District, Ontario. The lake tops out around 33 ft. The contours are modeled from the water's real shoreline and maximum depth. Treat them as a rough guide, and never use them for navigation. Species by species, here's what the data says the year looks like.
The outline encloses 1,077 acres, worked by 13 miles of shoreline — 2 islands included. An index of 2.8 puts the bank firmly in maze territory: point after pocket after cove, every one a casting target. The shallow band under 15 ft claims about 76% of the surface on the model — that's where the groceries are. End to end it runs roughly 2.9 mi, about 1.3 mi across. Thunder Bay District claims this one. Its nearest charted neighbour, Barge Lake, is 2 mi to the northwest.
In spring, cisco (lake herring) run shallow here, mostly 8 to 33 ft. Summer keeps them at 10 to 33 ft, and they winter in 10 to 33 ft. Spring cisco (lake herring) concentrate at Deep basin, a prime-rated deep basin around 28 ft. Fish it in early morning and you'll meet the bite. You won't need more than a vertical flutter spoon (small) or a drop-shot micro plastic most summer days.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 33 ft chart-limited; documented 10 to 40 ft | dawn & dusk | Deep basin (28 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 10 to 33 ft chart-limited; documented 40 to 80 ft | dawn | Deep basin (28 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (15 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 10 to 33 ft chart-limited; documented 20 to 60 ft | dawn | Deep basin (28 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
The spring pattern is a shallow one: walleye in 4 to 15 ft. As the season builds they drop to 10 to 33 ft, wintering in 10 to 33 ft. Top water on the chart: Break off the point, a drop-off in the 15 ft range, prime in fall. Time it for the evening and early morning. Summer baits: a crawler harness on bottom bouncer or a deep crankbait (trolled) gets it done.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| 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 | 10 to 33 ft chart-limited; documented 15 to 35 ft | dusk & dawn | Break off the point (15 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 10 to 33 ft chart-limited; documented 12 to 40 ft | dusk & night | Break off the point (15 ft) | Jigging rap, Jig + big minnow |
| Winter | 10 to 33 ft chart-limited; documented 20 to 40 ft | dusk & dawn | Deep basin (28 ft) | Jigging spoon + minnow head, Rattle bait |
In spring, yellow perch run shallow here, mostly 3 to 12 ft. Summer pushes them deeper, 10 to 30 ft, and winter fish settle into 10 to 33 ft. Shallow bay flat is the standout, a weed flat at roughly 4 ft, rated prime for spring yellow perch. Time it for early morning. You won't need more than a drop-shot micro plastics or a small spoon tipped with worm most summer days.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (4 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Deep basin (28 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 10 to 33 ft chart-limited; documented 12 to 35 ft | midday | Deep basin (28 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 10 to 33 ft chart-limited; documented 15 to 35 ft | midday & dawn | Deep basin (28 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Early season northern pike use the shallows, holding in 2 to 8 ft. Expect a summer slide to 8 to 20 ft, then a winter hold in 5 to 15 ft. Put Shallow bay flat first on the milk run — a weed flat near 4 ft that grades prime for spring. In summer the feeding windows fall in early morning and the evening. Tie on a bucktail or a weedless spoon over cabbage and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (4 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (15 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (15 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (4 ft) | Tip-ups, Large jigging spoon |
In spring, rock bass run shallow here, mostly 2 to 10 ft. Midsummer fish sit out in 5 to 20 ft before dropping to 12 to 30 ft for winter. Summer rock bass concentrate at Main-lake point, a prime-rated point around 8 ft. Fish it in the evening and you'll meet the bite. You won't need more than a ned rig (small) or a marabou jig most summer days.
| 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 | Break off the point (15 ft) | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Deep basin (28 ft) | Tungsten jig + plastic, Small spoon + spike |
Spring burbot on Post Lake hold shallow, usually 10 to 33 ft. Depth-wise the year is flat: 10 to 33 ft in summer, 8 to 33 ft once it turns cold. Put Deep basin first on the milk run — a deep basin near 28 ft that grades prime for spring. The feeding windows run after dark and midday. The summer box starts with a heavy jig + cut bait.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 33 ft chart-limited; documented 25 to 70 ft | night & dusk | Deep basin (28 ft) | Glow jigging spoon + cut bait, Rattle bait (dark) |
| Summer | 10 to 33 ft chart-limited; documented 50 to 120 ft | night & midday | Deep basin (28 ft) | Heavy jig + cut bait |
| Fall | 10 to 33 ft chart-limited; documented 30 to 80 ft | night & dusk | Deep basin (28 ft) | Glow spoon + minnow head, Blade bait (slow) |
| Winter | 8 to 33 ft chart-limited; documented 15 to 60 ft | night & dusk | Deep basin (28 ft) | Glow tungsten + cut bait, Rattle spoon + minnow head |
Structure-wise the chart holds 6 features, led in depth by Deep basin at roughly 28 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 Post Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Post Lake is about 33 ft (10 m) deep at its deepest point. The contours here are modeled from the water's real shape and maximum depth, so treat them as a rough guide.
Anglers target cisco (lake herring), walleye, yellow perch, northern pike, rock bass, burbot on Post Lake.
Deep basin is the top-rated area: a deep basin in about 28 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 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 Post 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.
Barge Lake 2 mi · Glitter L. 4 mi · Quest L. 4 mi · Princess Lake 6 mi · Six Mile Lake 7 mi · Willow L. 8 mi · Bell Lake 8 mi · Sturgeon Lake 9 mi · Vista L. 10 mi · Darkwater Lake 10 mi · Jessie Lake 12 mi · Cutstone Lake 12 mi
See how Post Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch lakes in Ontario · best burbot lakes in Ontario
More water nearby: Thunder Bay District fishing maps (662 charts). Browse all Ontario fishing maps. See every water on DepthScout. 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.