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Fishing O'Sullivan Lake: what the data says
10,365-acre lake near Ontario. The lake tops out around 150 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. Here is how the season plays out for each species, straight from the data behind the map.
Lake Trout fishing at O'Sullivan Lake
Start shallow in spring: lake trout sit in 10 to 40 ft that time of year. They move out to 50 to 120 ft in summer and finish the year down in 20 to 80 ft. If you only fish one area, make it Rock reef: a rock pile around 8.206471288391572 ft that scores prime in fall. Plan around early morning in the warm months. Tie on a white tube jig (deep) or a magnum spoon on downrigger and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 50 to 120 ft | dawn | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | White tube jig, Airplane jig |
Lake Whitefish fishing at O'Sullivan Lake
In spring, lake whitefish run shallow here, mostly 15 to 45 ft. Summer pushes them deeper, 40 to 90 ft, and winter fish settle into 25 to 70 ft. Rock reef is the standout, a rock pile at roughly 8.206471288391572 ft, rated prime for fall lake whitefish. Best bite is early morning. Tie on a blade bait vertical or a small jigging spoon and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 15 to 45 ft | midday & dawn | Small jig + waxworm, Blade bait (small) |
| Summer | 40 to 90 ft | dawn | Blade bait vertical, Small jigging spoon |
| Fall | 8 to 30 ft | dusk | Small spoon (gold), Jig + plastic larva |
| Winter | 25 to 70 ft | midday & dawn | Jigging spoon + bead chain, Tungsten jig + waxie |
Cisco (Lake Herring) fishing at O'Sullivan Lake
Spring cisco (lake herring) on O'Sullivan Lake hold shallow, usually 10 to 40 ft. By summer they slide out to 40 to 80 ft, and by winter most fish are in 20 to 60 ft. Rock reef is the standout, a rock pile at roughly 8.206471288391572 ft, rated prime for fall 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 | Go-to baits |
|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Small silver spoon, Tiny swim jig (white) |
| Summer | 40 to 80 ft | dawn | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Small casting spoon, Inline spinner (silver) |
| Winter | 20 to 60 ft | dawn | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
Walleye fishing at O'Sullivan Lake
Start shallow in spring: walleye sit in 4 to 15 ft that time of year. Summer pushes them deeper, 15 to 35 ft, and winter fish settle into 20 to 40 ft. The spot to know is Offshore hump, a offshore hump in about 15.362559951596262 ft of water that rates prime for walleye in summer. In summer the feeding windows fall in the evening and early morning. Tie on a crawler harness on bottom bouncer or a deep crankbait (trolled) and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Jigging spoon + minnow head, Rattle bait |
Yellow Perch fishing at O'Sullivan Lake
Start shallow in spring: yellow perch sit in 3 to 12 ft that time of year. By summer they slide out to 10 to 30 ft, and by winter most fish are in 15 to 35 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 6 ft that scores prime in spring. In summer the feeding windows fall in early morning. A drop-shot micro plastics or a small spoon tipped with worm covers the summer program.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Tungsten jig + spikes, Rattle spoon (small) |
Northern Pike fishing at O'Sullivan Lake
Start shallow in spring: northern pike sit in 2 to 8 ft that time of year. Summer pushes them deeper, 8 to 20 ft, and winter fish settle into 5 to 15 ft. Shallow bay flat is the standout, a weed flat at roughly 6 ft, rated prime for spring northern pike. Best bite is early morning and the evening. Summer baits: a bucktail or a weedless spoon over cabbage gets it done.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Tip-ups, Large jigging spoon |
O'Sullivan Lake also holds burbot (50 to 120 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Notable structure
- Deep basin: deep basin, around 128 ft
- Break off the point: drop-off, around 68 ft
- Sharp break: drop-off, around 52.462526128353375 ft
- Main-lake point: point, around 38 ft
- Secondary point: point, around 38 ft
- Sharp break: drop-off, around 34.88165380128697 ft
- Offshore hump: offshore hump, around 15.362559951596262 ft
- Rock reef: rock pile, around 8.206471288391572 ft
- Shallow bay flat: weed flat, around 6 ft
- Back-bay flat: weed flat, around 6 ft
- Rock reef: rock pile, around 3.026573289995836 ft
- Weed flat: weed flat, around 2.3143624286779185 ft
Common questions
How deep is O'Sullivan Lake?
O'Sullivan Lake is about 150 ft 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.
What fish are in O'Sullivan Lake?
Anglers target walleye, northern pike, yellow perch, lake trout, lake whitefish, burbot, cisco (lake herring) on O'Sullivan Lake.
Where is the best fishing spot on O'Sullivan Lake?
Rock reef is the top-rated area: a rock pile in about 8.206471288391572 ft of water that rates prime for lake whitefish in fall. Open the map above to see every rated spot for each species and season.
When is the best time to fish O'Sullivan Lake?
For lake trout, 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.
Nearby waters
Boston Lake · Hanover Lake · Lucy Lake · Esnagami Lake · Clover Lake · Durer Lake
See how O'Sullivan Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch lakes in Ontario · best lake trout lakes in Ontario
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