Shared by DepthScout anglers. Exact spots stay private, always.
169-acre lake in Parry Sound District, Ontario. The lake tops out around 40 ft. The depth data here comes from a transect sounding survey by the Ontario MNRF. What the data behind the map says about each species, season by season:
Traced from the shoreline, Grundy Lake runs 170 acres with 3.5 miles of edge. Index 1.9 on the shoreline: a few honest points and pockets, nothing labyrinthine. Roughly 50% of the water is 15 ft or less, the band where the food chain lives. Tip to tip the water measures near 1.1 mi with a 0.6-mi widest point. You'll find it in Parry Sound District. The nearest mapped water is Gurd Lake, 1 mi to the southeast.
When the water first warms, cisco (lake herring) slide up into 10 to 40 ft. There's no big seasonal slide here — summer means 12 to 40 ft, winter 12 to 40 ft. Start at Deep basin. It's a deep basin holding about 38 ft of water and rates prime come spring. The feeding windows run early morning. Keep a vertical flutter spoon (small) or a drop-shot micro plastic rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Deep basin (38 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 12 to 40 ft | dawn | Deep basin (38 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (16 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 12 to 40 ft | dawn | Deep basin (38 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 Break off the point first on the milk run — a drop-off near 16 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 | Break off the point (16 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Break off the point (16 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Deep basin (38 ft) | Jigging spoon + minnow head, Rattle bait |
Spring yellow perch on Grundy Lake hold shallow, usually 3 to 12 ft. They move out to 10 to 30 ft in summer and finish the year down in 15 to 35 ft. Put Shallow bay flat first on the milk run — a weed flat near 3 ft that grades prime for spring. The feeding windows run early morning. The summer box starts with a drop-shot micro plastics or a small spoon tipped with worm.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (3 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (16 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (16 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Deep basin (38 ft) | Tungsten jig + spikes, Rattle spoon (small) |
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 3 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 (3 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (16 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (16 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (3 ft) | Tip-ups, Large jigging spoon |
Spring puts smallmouth bass in skinny water — 3 to 12 ft is the zone. Warm water sends them out to 10 to 30 ft; cold water stacks them in 12 to 40 ft. Secondary point is the standout, a point at roughly 16 ft, rated prime for fall smallmouth bass. Plan around early morning and the evening in the warm months. A drop shot (goby/minnow) or a ned rig covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Main-lake point (4 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (16 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Secondary point (16 ft) | Jerkbait, Blade bait |
| Winter | 12 to 40 ft | midday | Break off the point (16 ft) | Blade bait, Hair jig |
In spring, largemouth bass run shallow here, mostly 2 to 10 ft. Midsummer fish sit out in 8 to 20 ft before dropping to 15 to 35 ft for winter. Spring largemouth bass concentrate at Shallow bay flat, a prime-rated weed flat around 3 ft. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a texas-rigged 10" worm or a deep-diving crankbait most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | dawn & dusk | Shallow bay flat (3 ft) | Spinnerbait, Chatterbait |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (16 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Main-lake point (4 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 15 to 35 ft | midday | Break off the point (16 ft) | Blade bait, Jigging spoon |
Grundy Lake also holds rock bass (5 to 20 ft in summer), crappie (10 to 25 ft in summer), pumpkinseed (2 to 10 ft in summer), brown bullhead (3 to 12 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Grundy Lake carries 6 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 38 ft down.
Access data: OpenStreetMap contributors (ODbL) — community-mapped launches. Confirm conditions and fees locally before you launch.
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 Grundy Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Grundy Lake is about 40 ft (12 m) deep at its deepest point. The depth data here comes from a transect sounding survey by the Ontario MNRF.
Anglers target cisco (lake herring), walleye, yellow perch, northern pike, smallmouth bass, largemouth bass, rock bass, crappie, pumpkinseed, brown bullhead on Grundy Lake.
Deep basin is the top-rated area: a deep basin in about 38 ft of water that rates prime for cisco (lake herring) in spring. The map above holds the full rated-spot list for every species and season.
For cisco (lake herring), 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.
Fishing on Grundy 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.
Gurd Lake 1 mi · Gut Lake 1 mi · Clear Lake 1 mi · Beaver Lake 1 mi · Bucke Lake 2 mi · Pakeshkag Lake 2 mi · Portage Lake 2 mi · Nisbet Lake 3 mi · Ham Lake 8 mi · Byrne Lake 10 mi · Cole Lake 11 mi · North Channel (French River) 12 mi
See how Grundy Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best northern pike lakes in Ontario
More water nearby: Parry Sound District fishing maps (441 charts). Browse all Ontario fishing maps or see every water on DepthScout. Bathymetry credit: state fisheries survey programs. 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.