Mary L. Depth Map & Fishing Spots (ON)

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Lake depth chart

Mary L., ON

Max 34 ft

Today's read

Where to start

Fall shiner run window is on — see the hatch outlook

Hatch outlook

Fall shiner runActive window

Typical here: Sep 1 – Oct 31 · same push on the Ontario side — Simcoe's shiners migrate shallow as the water cools, and the predators ride with them

adultdaylight for the jig bite; after dark the shiners stack under dock lights with walleyes and pike mixed right in — follow the bait, not the spot — millions of shiners move together and the predators ride with them; silver profile and flash matter

Concentrates hard but travels — the school (and the walleyes under it) can be off a river mouth one week and miles upriver the next.

Jig-and-minnow is the event's signature — a frozen emerald shiner on a 1/4 oz jig drifted along the run; silver jerkbaits and trolled crankbaits take the roaming fish; blade baits under the schools.

The event happens over river mouths and the first miles upriver, warming shallow shorelines, and rocky points where the displaced bait stacks

Next on this water

Hex (giant mayfly) · mayflyMay 25 – Aug 10 · in ~9 months

June mayfly hatch (walleye lakes) · mayflyJun 1 – Aug 10 · in ~9 months

Recommendations come from depth structure and seasonal species behavior. Treat them as a starting point, not a guarantee. Contours on this water are approximations. Never use for navigation. Always check local regulations.

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Recent catches at Mary L.

Shared by DepthScout anglers. Exact spots stay private, always.

No shared catches here yet — be the first.Log a catch from the map above and share it to put Mary L. on the board.

Fishing Mary L.: what the data says

22-acre lake in Cochrane District, Ontario. The lake tops out around 34 ft. This chart interpolates between a real shoreline and a known maximum depth. It will point you at likely water, but it is not a navigation product. The rest of this page walks each species through its year, using the map's own scoring.

Mary L. maps at 22 acres behind 1.4 miles of shoreline. A middling shoreline index (2.1) gives it some bays to work without being a maze. 53% of the surface is littoral (under ~15 ft), per the model — cover, weeds and forage water. Figure 0.4 mi of water from one end to the other, 0.2 mi at the beam. It sits in Cochrane District. Mirky L. sits 1 mi northwest — the closest neighbouring chart.

Yellow Perch fishing at Mary L.

In spring, yellow perch run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 10 to 34 ft for winter. Fall yellow perch concentrate at Deep basin, a prime-rated deep basin around 29 ft. Fish it in early morning and you'll meet the bite. You won't need more than a drop-shot micro plastics or a small spoon tipped with worm most summer days.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 12 ft	midday & dawn	open water	Small jig + curly tail, Perch-pattern micro crank
Summer	10 to 30 ft	dawn	Deep basin (29 ft)	Drop-shot micro plastics, Small spoon tipped with worm
Fall	10 to 34 ft	midday	Deep basin (29 ft)	Jigging spoon (small), Perch rig / spreader
Winter	10 to 34 ft	midday & dawn	Deep basin (29 ft)	Tungsten jig + spikes, Rattle spoon (small)

Notable structure

Mary L. carries 4 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 29 ft down.

Deep basin: deep basin, around 29 ft
Break off the point: drop-off, around 15 ft
Main-lake point: point, around 9 ft
Secondary point: point, around 9 ft

Mary L. fishing regulations

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 Mary L. specifically, so confirm the current rules before you fish.

Check the official Ontario fishing regulations →

Common questions

How deep is Mary L.?

Mary L. is about 34 ft (10 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.

What fish are in Mary L.?

Anglers target yellow perch on Mary L..

Where is the best fishing spot on Mary L.?

Deep basin is the top-rated area: a deep basin in about 29 ft of water that rates prime for yellow perch in fall. The map above holds the full rated-spot list for every species and season.

When is the best time to fish Mary L.?

For yellow perch, 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.

What are the fishing regulations for Mary L.?

Fishing on Mary L. 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.

Nearby waters

Mirky L. 1 mi · Cooke L. 1 mi · Marathon Lake 1 mi · Trusz L. 1 mi · Marilyn L. 1 mi · Anne L. 2 mi · Dungg L. 2 mi · Lake 12L-17 4 mi · Watton L. 4 mi · Upper Bingle Lake 4 mi · Lake 12L-12 4 mi · Lake 12L-11 4 mi

See how Mary L. stacks up: best yellow perch lakes in Ontario

More water nearby: Cochrane District fishing maps (673 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.