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823-acre lake in Thunder Bay District, Ontario. The lake tops out around 25 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. Every species below gets its seasonal read from the same numbers driving the chart.
On the chart, McGrath Lake draws 824 acres inside 11.2 miles of shoreline, broken up by 3 islands. The 2.8 development index tells the story — a convoluted bank whose fishable edge far outruns the acreage. Nothing on this chart breaks 15 ft, which makes the whole surface littoral: weeds, bait and ambush cover everywhere. Call it 2 mi long by 1.3 mi wide at the broadest reach. The water lies in Thunder Bay District. Closest neighbour on DepthScout: Blunder Lake, 1 mi north of here.
Spring walleye on McGrath Lake hold shallow, usually 4 to 15 ft. They move out to 8 to 25 ft in summer and finish the year down in 8 to 25 ft. Put Deep basin first on the milk run — a deep basin near 20 ft that grades prime for winter. The feeding windows run the evening and early morning. The summer box starts with a crawler harness on bottom bouncer or a deep crankbait (trolled).
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 | 4 to 15 ft | dusk & dawn | Main-lake point (1 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 8 to 25 ft chart-limited; documented 15 to 35 ft | dusk & dawn | Deep basin (20 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 8 to 25 ft chart-limited; documented 12 to 40 ft | dusk & night | Deep basin (20 ft) | Jigging rap, Jig + big minnow |
| Winter | 8 to 25 ft chart-limited; documented 20 to 40 ft | dusk & dawn | Deep basin (20 ft) | Jigging spoon + minnow head, Rattle bait |
Early season yellow perch use the shallows, holding in 3 to 12 ft. Expect a summer slide to 8 to 25 ft, then a winter hold in 8 to 25 ft. Put Deep basin first on the milk run — a deep basin near 20 ft that grades prime for fall. In summer the feeding windows fall in early morning. Tie on a drop-shot micro plastics or a small spoon tipped with worm and you're in the game.
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 | 3 to 12 ft | midday & dawn | Shallow bay flat (1 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 8 to 25 ft chart-limited; documented 10 to 30 ft | dawn | Deep basin (20 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 8 to 25 ft chart-limited; documented 12 to 35 ft | midday | Deep basin (20 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 8 to 25 ft chart-limited; documented 15 to 35 ft | midday & dawn | Deep basin (20 ft) | Tungsten jig + spikes, Rattle spoon (small) |
In spring, northern pike run shallow here, mostly 2 to 8 ft. 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 1 ft, rated prime for spring northern pike. Time it for early morning and the evening. 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 (1 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | open water | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Shallow bay flat (1 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (1 ft) | Tip-ups, Large jigging spoon |
6 pieces of structure are mapped here — Deep basin, around 20 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 McGrath Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
McGrath Lake is about 25 ft (8 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 walleye, yellow perch, northern pike on McGrath Lake.
Deep basin is the top-rated area: a deep basin in about 20 ft of water that rates prime for walleye in winter. Every other rated spot, per species and season, is on the map above.
For walleye, the summer bite is best in the evening and 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 McGrath 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.
Blunder Lake 1 mi · Chambers Lake 1 mi · Amethyst Lake 2 mi · Swallow Lake 4 mi · Topaz Lake 4 mi · Batwing Lake 5 mi · Kamikau Lake 7 mi · Weikwabinonaw Lake 8 mi · Flatrock Lake 8 mi · Kekekuab Lake 8 mi · Highcliff Lake 9 mi · Tinto Lake 9 mi
See how McGrath Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch lakes in Ontario
More water nearby: Thunder Bay District fishing maps (662 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.