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2,311-acre lake in Rainy River District, Ontario. The lake tops out around 121 ft. The chart is a model: real shoreline, published maximum depth, interpolated in between. A planning tool, never a navigation product. What the data behind the map says about each species, season by season:
On the chart, Thompson Lake draws 2,314 acres inside 26.8 miles of shoreline — 4 islands included. The 4 development index tells the story — a convoluted bank whose fishable edge far outruns the acreage. 26% of the surface is littoral (under ~15 ft), per the model — cover, weeds and forage water. Figure 4.6 mi of water from one end to the other, 1.8 mi at the beam. You'll find it in Rainy River District. The nearest mapped water is David Lake, 5 mi to the west.
The spring pattern is a shallow one: lake trout in 10 to 40 ft. Midsummer fish sit out in 50 to 120 ft before dropping to 20 to 80 ft for winter. The spot to know is Deep basin, a deep basin in about 103 ft of water that rates prime for lake trout in summer. Plan around early morning in the warm months. Summer baits: a white tube jig (deep) or a magnum spoon on downrigger gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Main-lake point (30 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 50 to 120 ft | dawn | Deep basin (103 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Main-lake point (30 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | Break off the point (54 ft) | White tube jig, Airplane jig |
Come spring, look for cisco (lake herring) tight to the bank in 10 to 40 ft. They move out to 40 to 80 ft in summer and finish the year down in 20 to 60 ft. If you only fish one area, make it Break off the point: a drop-off around 54 ft that scores prime in winter. 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 | 10 to 40 ft | dawn & dusk | open water | Small silver spoon, Tiny swim jig (white) |
| Summer | 40 to 80 ft | dawn | Break off the point (54 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | open water | Small casting spoon, Inline spinner (silver) |
| Winter | 20 to 60 ft | dawn | Break off the point (54 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
Spring walleye on Thompson Lake hold shallow, usually 4 to 15 ft. By summer they slide out to 15 to 35 ft, and by winter most fish are in 20 to 40 ft. The chart's best answer is Main-lake point — point, 30 ft, prime for fall. Prime time lands in the evening and early morning. The summer box starts with a crawler harness on bottom bouncer or a deep crankbait (trolled).
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | open water | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Main-lake point (30 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Main-lake point (30 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Main-lake point (30 ft) | Jigging spoon + minnow head, Rattle bait |
Early season yellow perch use the shallows, holding in 3 to 12 ft. Summer is a 10 to 30 ft game here, winter a 15 to 35 ft one. The chart's best answer is Shallow bay flat — weed flat, 6 ft, prime for spring. 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 (6 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Shallow bay flat (6 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | open water | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | open water | Tungsten jig + spikes, Rattle spoon (small) |
In spring, northern pike run shallow here, mostly 2 to 8 ft. Midsummer fish sit out in 8 to 20 ft before dropping to 5 to 15 ft for winter. Spring northern pike concentrate at Shallow bay flat, a prime-rated weed flat around 6 ft. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a bucktail or a weedless spoon over cabbage most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (6 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Shallow bay flat (6 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Shallow bay flat (6 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (6 ft) | Tip-ups, Large jigging spoon |
In spring, smallmouth bass run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 20 to 45 ft for winter. Summer smallmouth bass concentrate at Main-lake point, a prime-rated point around 30 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 | open water | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (30 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (30 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Break off the point (54 ft) | Blade bait, Hair jig |
Thompson Lake also holds largemouth bass (8 to 20 ft in summer), rock bass (5 to 20 ft in summer), bluegill (4 to 15 ft in summer), pumpkinseed (2 to 10 ft in summer), burbot (50 to 120 ft in summer). Pick any of them on the map above for rated spots and bait picks.
6 pieces of structure are mapped here — Deep basin, around 103 ft, is the deepest of them.
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 Thompson Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Thompson Lake is about 121 ft (37 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 lake trout, cisco (lake herring), walleye, yellow perch, northern pike, smallmouth bass, largemouth bass, rock bass, bluegill, pumpkinseed, burbot on Thompson Lake.
Deep basin is the top-rated area: a deep basin in about 103 ft of water that rates prime for lake trout in summer. The interactive chart above rates every spot for each species and season.
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.
Fishing on Thompson 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.
David Lake 5 mi · Trygg 5 mi, MN · Gun 6 mi, MN · Steep 6 mi, MN · Spring L. 6 mi · Eugene 6 mi, MN · Captain Tom Lake 7 mi · Takucmich 7 mi, MN · Beartrack 7 mi, MN · Fat 7 mi, MN · Lilac Lake 7 mi · Trout Lake 7 mi
See how Thompson Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best northern pike lakes in Ontario
More water nearby: Rainy River District fishing maps (257 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.