Shared by DepthScout anglers. Exact spots stay private, always.
507-acre lake near Ontario. The lake tops out around 105 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.
Start shallow in spring: cisco (lake herring) sit in 10 to 40 ft that time of year. By summer they slide out to 40 to 80 ft, and by winter most fish are in 20 to 60 ft. Deep basin is the standout, a deep basin at roughly 89 ft, rated prime for summer 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 |
Spring yellow perch on Thirty Island Lake hold shallow, usually 3 to 12 ft. They move out to 10 to 30 ft in summer and finish the year down in 15 to 35 ft. Shallow bay flat is the standout, a weed flat at roughly 6 ft, rated prime for spring yellow perch. 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 | 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) |
Start shallow in spring: northern pike sit in 2 to 8 ft that time of year. They move out to 8 to 20 ft in summer and finish the year down in 5 to 15 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 6 ft that scores prime in spring. Plan around early morning and the evening in the warm months. A bucktail or a weedless spoon over cabbage covers the summer program.
| 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 |
In spring, smallmouth bass run shallow here, mostly 3 to 12 ft. Summer pushes them deeper, 10 to 30 ft, and winter fish settle into 20 to 45 ft. Main-lake point is the standout, a point at roughly 26 ft, rated prime for fall smallmouth bass. Best bite is early morning and the evening. Tie on a drop shot (goby/minnow) or a ned rig and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Blade bait, Hair jig |
In spring, largemouth bass run shallow here, mostly 2 to 10 ft. Summer pushes them deeper, 8 to 20 ft, and winter fish settle into 15 to 35 ft. Shallow bay flat is the standout, a weed flat at roughly 6 ft, rated prime for spring largemouth bass. Best bite is early morning and the evening. Tie on a texas-rigged 10" worm or a deep-diving crankbait and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 2 to 10 ft | dawn & dusk | Spinnerbait, Chatterbait |
| Summer | 8 to 20 ft | dawn & dusk | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Squarebill crankbait (shad), Spinnerbait |
| Winter | 15 to 35 ft | midday | Blade bait, Jigging spoon |
In spring, rock bass run shallow here, mostly 2 to 10 ft. Summer pushes them deeper, 5 to 20 ft, and winter fish settle into 12 to 30 ft. Main-lake point is the standout, a point at roughly 26 ft, rated good for fall rock bass. Best bite is the evening. Tie on a ned rig (small) or a marabou jig and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | 1/16 oz jig + grub, Small inline spinner |
| Summer | 5 to 20 ft | dusk | Ned rig (small), Marabou jig |
| Fall | 8 to 22 ft | midday | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Tungsten jig + plastic, Small spoon + spike |
Thirty Island Lake also holds bluegill (4 to 15 ft in summer), pumpkinseed (2 to 10 ft in summer), burbot (32 to 105 ft in summer). Pick any of them on the map above for rated spots and bait picks.
How deep is Thirty Island Lake?
Thirty Island Lake is about 105 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 Thirty Island Lake?
Anglers target largemouth bass, smallmouth bass, northern pike, bluegill, yellow perch, burbot, rock bass, cisco (lake herring), pumpkinseed on Thirty Island Lake.
Where is the best fishing spot on Thirty Island Lake?
Shallow bay flat is the top-rated area: a weed flat in about 6 ft of water that rates prime for yellow perch in spring. Open the map above to see every rated spot for each species and season.
When is the best time to fish Thirty Island Lake?
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.
Sand Lake · Sangster Lake · White Lake · Desert Lake · Miner Lake · Potspoon Lake
See how Thirty Island Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best northern pike lakes in Ontario · best bluegill lakes in Ontario
Browse all Ontario fishing maps or every water on DepthScout. How we build these maps. For fishing guidance only, never navigation.