Sign inSign up free Sign inSign up free Sign inSign up freeLake depth chart
Today's read
Recent public catches load as you reach this section.
38-acre lake in Algoma District, Ontario. The lake tops out around 72 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. The depth data here comes from the Ontario MNRF survey of 1981 (a transect sounding survey). Here is how the season plays out for each species, straight from the data behind the map.
Traced from the shoreline, Mash Lake runs 39 acres with 2.8 miles of edge — 2 islands included. An index of 3.2 puts the bank firmly in maze territory: point after pocket after cove, every one a casting target. 61% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. The basin spans about 0.8 mi end to end and 0.3 mi across at its widest. You'll find it in Algoma District. Closest neighbour on DepthScout: Black Lake, 3 mi northeast of here.
Start shallow in spring: brook trout sit in 2 to 15 ft that time of year. Summer pushes them deeper, 10 to 30 ft, and winter fish settle into 3 to 20 ft. The spot to know is Main-lake point, a point in about 4 ft of water that rates prime for brook trout in spring. Warm-month bites cluster around early morning and the evening. Throw a small spoon fished deep or a trolled lake-clear wobbler + worm until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 15 ft | dawn & dusk | Main-lake point (4 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (7 ft) | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 2 to 15 ft | midday & dawn | Main-lake point (4 ft) | Small spoon (orange), Spinner |
| Winter | 3 to 20 ft | dawn | Break off the point (7 ft) | Small jigging spoon, Tungsten jig + plastic |
Start shallow in spring: lake trout sit in 10 to 40 ft that time of year. Warm water sends them out to 22 to 72 ft; cold water stacks them in 18 to 72 ft. Top water on the chart: Deep basin, a deep basin in the 66 ft range, prime in summer. Fish it in early morning and you'll meet the bite. Throw a white tube jig (deep) or a magnum spoon on downrigger until the fish tell you otherwise.
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 | 10 to 40 ft | dawn & dusk | Secondary point (18 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 22 to 72 ft chart-limited; documented 50 to 120 ft | dawn | Deep basin (66 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Secondary point (18 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 18 to 72 ft chart-limited; documented 20 to 80 ft | dawn | Deep basin (66 ft) | White tube jig, Airplane jig |
When the water first warms, cisco (lake herring) slide up into 10 to 40 ft. Summer is a 22 to 72 ft game here, winter a 20 to 60 ft one. Start at Deep basin. It's a deep basin holding about 66 ft of water and rates prime come summer. The feeding windows run early morning. Keep a vertical flutter spoon (small) or a drop-shot micro plastic rigged through the warm months.
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 | 10 to 40 ft | dawn & dusk | Break off the point (7 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 22 to 72 ft chart-limited; documented 40 to 80 ft | dawn | Deep basin (66 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (7 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 20 to 60 ft | dawn | Deep basin (66 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
Early season walleye use the shallows, holding in 4 to 15 ft. Expect a summer slide to 15 to 35 ft, then a winter hold in 20 to 40 ft. Put Secondary point first on the milk run — a point near 18 ft that grades prime for fall. In summer the feeding windows fall in the evening and early morning. Tie on a crawler harness on bottom bouncer or a deep crankbait (trolled) and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (4 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Secondary point (18 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Secondary point (18 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Secondary point (18 ft) | Jigging spoon + minnow head, Rattle bait |
Spring puts northern pike in skinny water — 2 to 8 ft is the zone. Warm water sends them out to 8 to 20 ft; cold water stacks them in 5 to 15 ft. Shallow bay flat is the standout, a weed flat at roughly 4 ft, rated prime for spring northern pike. 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 | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (4 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Secondary point (18 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (7 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (4 ft) | Tip-ups, Large jigging spoon |
Start shallow in spring: burbot sit in 25 to 70 ft that time of year. Warm water sends them out to 22 to 72 ft; cold water stacks them in 15 to 60 ft. Top water on the chart: Deep basin, a deep basin in the 66 ft range, prime in spring. Fish it in after dark and midday and you'll meet the bite. Throw a heavy jig + cut bait until the fish tell you otherwise.
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 | 25 to 70 ft | night & dusk | Deep basin (66 ft) | Glow jigging spoon + cut bait, Rattle bait (dark) |
| Summer | 22 to 72 ft chart-limited; documented 50 to 120 ft | night & midday | Deep basin (66 ft) | Heavy jig + cut bait |
| Fall | 22 to 72 ft chart-limited; documented 30 to 80 ft | night & dusk | Deep basin (66 ft) | Glow spoon + minnow head, Blade bait (slow) |
| Winter | 15 to 60 ft | night & dusk | Deep basin (66 ft) | Glow tungsten + cut bait, Rattle spoon + minnow head |
Count 5 structure marks on this chart. The deepest, Deep basin, sits near 66 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 Mash Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Mash Lake is about 72 ft (22 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1981 (a transect sounding survey).
Anglers target brook trout, lake trout, cisco (lake herring), walleye, northern pike, burbot on Mash Lake. This isn't a survey of the lake — none is on record for it — but an informed estimate from the species Ontario's MNRF recorded in the nearest surveyed lakes, filtered to this lake's depth and habitat.
Deep basin is the top-rated area: a deep basin in about 66 ft of water that rates prime for lake trout in summer. The map above holds the full rated-spot list for every 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 Mash 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.
Black Lake 3 mi · Hardtime Lake 3 mi · Old Woman Lake 3 mi · Slievert Lake 4 mi · Wildcat Lake 5 mi · Dead Otter Lake 5 mi · Gamitagama Lake 5 mi · Belanger Lake 5 mi · Doc Greig Lake 7 mi · Gargantua Lake 7 mi · Buckshot Lake 7 mi · Fife Lake 7 mi
See how Mash Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best lake trout lakes in Ontario · 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.