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Rating depth structure for brook trout.
Recent public catches load as you reach this section.
21-acre lake in Algoma District, Ontario. The lake tops out around 10 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. Here's the year, species by species, as the scoring engine sees it.
Drawn out, this is 21 acres of water rimmed by 0.9 miles of bank. Nearly circular (index 1.4), so the story is the bottom, not the bank. The whole water is littoral — nothing here runs deeper than ~15 ft, so it's all weed-and-bait territory. End to end it runs roughly 0.3 mi, about 0.2 mi across. You'll find it in Algoma District. For a second option, Big Skunk Lake lies 1 mi west.
The spring pattern is a shallow one: brook trout in 1 to 10 ft. The depth story barely changes: 3 to 10 ft through summer, 2 to 10 ft in winter. Top water on the chart: Deep basin, a deep basin in the 10 ft range, prime in summer. Time it for early morning and the evening. Summer baits: a small spoon fished deep or a trolled lake-clear wobbler + worm 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 | 1 to 10 ft chart-limited; documented 2 to 15 ft | dawn & dusk | Shallow bay flat (1 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 3 to 10 ft chart-limited; documented 10 to 30 ft | dawn & dusk | Deep basin (10 ft) | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 1 to 10 ft chart-limited; documented 2 to 15 ft | midday & dawn | open water | Small spoon (orange), Spinner |
| Winter | 2 to 10 ft chart-limited; documented 3 to 20 ft | dawn | Deep basin (10 ft) | Small jigging spoon, Tungsten jig + plastic |
The chart marks 4 structure features on Johnston Lake; the deepest is Deep basin at about 10 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 Johnston Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Johnston Lake is about 10 ft (3 m) deep at its deepest point. 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.
Anglers target brook trout on Johnston Lake.
Deep basin is the top-rated area: a deep basin in about 10 ft of water that rates prime for brook trout in summer. Every other rated spot, per species and season, is on the map above.
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 Johnston 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.
Big Skunk Lake 1 mi · Martin Lake 1 mi · Freddie Lake 1 mi · Fisher Lake 1 mi · Mink Lake 2 mi · Mole Lake 2 mi · Souter Lake 3 mi · Starling Lake 3 mi · Lapworth Lake 3 mi · Arnott Lake 3 mi · Gagnon Lake 3 mi · Corine Lake 3 mi
See how Johnston Lake stacks up: best brook trout lakes in Ontario
More water nearby: Algoma District fishing maps (1026 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.