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1,068-acre lake in Rainy River District, Ontario. The lake tops out around 33 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 1978, a decades-old survey (an MNRF lake survey). Here's the year, species by species, as the scoring engine sees it.
Osinawi Lake maps at 1,072 acres behind 17.6 miles of shoreline, broken up by 4 islands. With a shoreline index of 3.8, this water is all arms and coves — edge habitat well beyond its acreage. All of it is shallow-zone water — under ~15 ft across the entire basin, so the food chain has the run of the place. The basin spans about 3 mi end to end and 1.7 mi across at its widest. It sits in Rainy River District. Tyrell Lake sits 3 mi northwest — the closest neighbouring chart.
The spring pattern is a shallow one: walleye in 4 to 15 ft. Midsummer fish sit out in 10 to 33 ft before dropping to 10 to 33 ft for winter. The spot to know is Deep basin, a deep basin in about 20 ft of water that rates prime for walleye in winter. Plan around the evening and early morning in the warm months. 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 (1 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 10 to 33 ft chart-limited; documented 15 to 35 ft | dusk & dawn | Deep basin (20 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 10 to 33 ft chart-limited; documented 12 to 40 ft | dusk & night | Deep basin (20 ft) | Jigging rap, Jig + big minnow |
| Winter | 10 to 33 ft chart-limited; documented 20 to 40 ft | dusk & dawn | Deep basin (20 ft) | Jigging spoon + minnow head, Rattle bait |
In spring, yellow perch run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 10 to 33 ft for winter. Fall yellow perch concentrate at Deep basin, a prime-rated deep basin around 20 ft. Fish it in early morning and you'll meet the bite. 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 feeding flat (7 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Deep basin (20 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 (20 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 10 to 33 ft chart-limited; documented 15 to 35 ft | midday & dawn | Deep basin (20 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Early season northern pike use the shallows, holding in 2 to 8 ft. Summer is an 8 to 20 ft game here, winter a 5 to 15 ft one. The chart's best answer is Shallow bay flat — weed flat, 1 ft, prime for spring. Best bite is 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 (1 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Shallow feeding flat (7 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Shallow feeding flat (7 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow feeding flat (7 ft) | Tip-ups, Large jigging spoon |
In spring, pumpkinseed run shallow here, mostly 1 to 8 ft. Summer pushes them deeper, 2 to 10 ft, and winter fish settle into 6 to 18 ft. Shallow bay flat is the standout, a weed flat at roughly 1 ft, rated prime for spring pumpkinseed. Time it for the evening and early morning. You won't need more than a micro tube or a sponge spider (fly) most summer days.
| 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 feeding flat (7 ft) | Micro jig + waxworm, Small spoon tipped |
| Winter | 6 to 18 ft | dawn | Shallow feeding flat (7 ft) | Tungsten ice jig + plastic, Tiny spoon |
Count 7 structure marks on this chart. The deepest, Deep basin, sits near 20 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 Osinawi Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Osinawi Lake is about 33 ft (10 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1978, a decades-old survey (an MNRF lake survey).
Anglers target walleye, yellow perch, northern pike, pumpkinseed on Osinawi Lake.
Deep basin is the top-rated area: a deep basin in about 20 ft of water that rates prime for walleye in winter. Open the map above to see every rated spot for each species and season.
For walleye, the summer bite is best in the evening and 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 Osinawi 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.
Tyrell Lake 3 mi · Sapawe Lake 3 mi · Bradshaw Lake 3 mi · Wife Lake 3 mi · Aramis Lake 4 mi · Letain Lake 4 mi · Husband Lake 4 mi · Smith Lake 5 mi · Plateau Lake 5 mi · Nickleby Lake 5 mi · Seine River 6 mi · Niobe Lake 6 mi
See how Osinawi Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch lakes in Ontario · best pumpkinseed lakes in Ontario
More water nearby: Rainy River District fishing maps (257 charts). Browse all Ontario fishing maps. 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.