Sign inSign up free Sign inSign up free Sign inSign up freeLake depth chart
Today's read
Shared by DepthScout anglers. Exact spots stay private, always.
32-acre lake in Haliburton County, Ontario. The lake tops out around 36 ft. Contours on this water are modeled from its actual shoreline and max depth. Good for finding likely water, never for navigation. Species by species, here's what the data says the year looks like.
Thumb Lake maps at 32 acres behind 2 miles of shoreline. That shoreline is heavily fingered (development index 2.5) — bays, points and pockets everywhere, which multiplies the fishable edge. Roughly 67% of the water is 15 ft or less as modeled, the band where the food chain lives. End to end it runs roughly 0.8 mi, about 0.2 mi across. It sits in Haliburton County. Its nearest charted neighbour, Lucy Lake, is 1 mi to the northwest.
When the water first warms, brook trout slide up into 2 to 15 ft. By summer they slide out to 10 to 30 ft, and by winter most fish are in 3 to 20 ft. If you only fish one area, make it Break off the point: a drop-off around 16 ft that scores prime in summer. In summer the feeding windows fall in early morning and the evening. Keep a small spoon fished deep or a trolled lake-clear wobbler + worm rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 15 ft | dawn & dusk | Main-lake point (9 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (16 ft) | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 2 to 15 ft | midday & dawn | Main-lake point (9 ft) | Small spoon (orange), Spinner |
| Winter | 3 to 20 ft | dawn | Break off the point (16 ft) | Small jigging spoon, Tungsten jig + plastic |
5 pieces of structure are mapped here — Deep basin, around 31 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 Thumb Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Thumb Lake is about 36 ft (11 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 brook trout on Thumb Lake.
Break off the point is the top-rated area: a drop-off in about 16 ft of water that rates prime for brook trout in summer. The interactive chart above rates every spot for each species and season.
For brook trout, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Thumb 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.
Lucy Lake 1 mi · Bright Lake 1 mi · Niger Lake 2 mi · Samlet Lake 3 mi · Park Lake 3 mi · Oxtongue Lake 3 mi · Victory Lake 3 mi · Martencamp Lake 3 mi · Eiler Lake 3 mi · West Ermine L. 4 mi · Fisher Lake 4 mi · Snow Lake 4 mi
See how Thumb Lake stacks up: best brook trout lakes in Ontario
More water nearby: Haliburton County fishing maps (295 charts). Browse all Ontario fishing maps or 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.