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241-acre lake in Lennox and Addington County, Ontario. The lake tops out around 98 ft. The depth data here comes from the Ontario MNRF survey of 1979, a decades-old survey (a transect sounding survey). Here is how the season plays out for each species, straight from the data behind the map.
Drawn out, this is 242 acres of water rimmed by 10 miles of bank, with 10 islands in the mix. With a shoreline index of 4.6, this water is all arms and coves — edge habitat well beyond its acreage. Littoral water — the productive band under ~15 ft — makes up 21% of this chart. Tip to tip the water measures near 3.1 mi with a 1.1-mi widest point. You'll find it in Lennox and Addington County. The nearest mapped water is Gull Lake, 1 mi to the east.
Spring walleye on Sheffield Long Lake hold shallow, usually 4 to 15 ft. By summer they slide out to 15 to 35 ft, and by winter most fish are in 20 to 40 ft. The chart's best answer is Main-lake point — point, 18 ft, prime for fall. Prime time lands in the evening and early morning. The summer box starts with a crawler harness on bottom bouncer or a deep crankbait (trolled).
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Secondary point (3 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Main-lake point (18 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Main-lake point (18 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Main-lake point (18 ft) | Jigging spoon + minnow head, Rattle bait |
Early season yellow perch use the shallows, holding in 3 to 12 ft. Summer is a 10 to 30 ft game here, winter a 15 to 35 ft one. The chart's best answer is Shallow bay flat — weed flat, 3 ft, prime for spring. Best bite is early morning. Tie on a drop-shot micro plastics or a small spoon tipped with worm and you're in the game.
| 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 | Feeding flat (22 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Deep basin (97 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Feeding flat (22 ft) | Tungsten jig + spikes, Rattle spoon (small) |
In spring, northern pike run shallow here, mostly 2 to 8 ft. Midsummer fish sit out in 8 to 20 ft before dropping to 5 to 15 ft for winter. Spring northern pike 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 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 (3 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Main-lake point (18 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Main-lake point (18 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 |
In spring, smallmouth bass run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 20 to 45 ft for winter. Fall smallmouth bass concentrate at Main-lake point, a prime-rated point around 18 ft. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a drop shot (goby/minnow) or a ned rig most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Secondary point (3 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (18 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (18 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Break off the point (51 ft) | Blade bait, Hair jig |
Spring puts largemouth bass in skinny water — 2 to 10 ft is the zone. Warm water sends them out to 8 to 20 ft; cold water stacks them in 15 to 35 ft. Shallow bay flat is the standout, a weed flat at roughly 3 ft, rated prime for spring largemouth bass. Plan around early morning and the evening in the warm months. A texas-rigged 10" worm or a deep-diving crankbait covers the summer program.
| 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 | Main-lake point (18 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Secondary point (3 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 15 to 35 ft | midday | Break off the point (51 ft) | Blade bait, Jigging spoon |
Come spring, look for rock bass tight to the bank in 2 to 10 ft. They move out to 5 to 20 ft in summer and finish the year down in 12 to 30 ft. If you only fish one area, make it Main-lake point: a point around 18 ft that scores prime in summer. Best bite is the evening. A ned rig (small) or a marabou jig is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | Secondary point (3 ft) | 1/16 oz jig + grub, Small inline spinner |
| Summer | 5 to 20 ft | dusk | Main-lake point (18 ft) | Ned rig (small), Marabou jig |
| Fall | 8 to 22 ft | midday | Main-lake point (18 ft) | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Deep basin (97 ft) | Tungsten jig + plastic, Small spoon + spike |
Sheffield Long Lake also holds crappie (10 to 25 ft in summer), bluegill (4 to 15 ft in summer), pumpkinseed (2 to 10 ft in summer), brown bullhead (3 to 12 ft in summer), burbot (29 to 98 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Structure-wise the chart holds 7 features, led in depth by Deep basin at roughly 97 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 Sheffield Long Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Sheffield Long Lake is about 98 ft (30 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1979, a decades-old survey (a transect sounding survey).
Anglers target walleye, yellow perch, northern pike, smallmouth bass, largemouth bass, rock bass, crappie, bluegill, pumpkinseed, brown bullhead, burbot on Sheffield Long Lake.
Shallow bay flat is the top-rated area: a weed flat in about 3 ft of water that rates prime for yellow perch in spring. Scroll up to the map for the complete spot list by species and season.
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 Sheffield Long 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.
Gull Lake 1 mi · Puzzle Lake 2 mi · Loyst Lake 3 mi · Norway Lake 4 mi · Mellon Creek 4 mi · Bear Lake 4 mi · Sixth Depot Lake 5 mi · Horseshoe Lake 6 mi · Beaver Lake 6 mi · Bull Lake 7 mi · Fifth Depot Lake 7 mi · Buck Lake 8 mi
See how Sheffield Long 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: Lennox and Addington County fishing maps (23 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.