Lake depth chart
Today's read
Recent public catches load as you reach this section.
174-acre lake in Frontenac County, Ontario. The lake tops out around 95 ft. The contours come from a model of the real basin shape and its known max depth. Read them as probabilities, not soundings, and keep them out of navigation decisions. Every species below gets its seasonal read from the same numbers driving the chart.
On the chart, Rock Lake draws 174 acres inside 5.4 miles of shoreline, with a single island in the mix. That shoreline is heavily fingered (development index 2.9) — bays, points and pockets everywhere, which multiplies the fishable edge. Roughly 51% of the water is 15 ft or less as modeled, the band where the food chain lives. Figure 1.1 mi of water from one end to the other, 0.6 mi at the beam. You'll find it in Frontenac County. Closest neighbour on DepthScout: Lake of the Hills, 1 mi southeast of here.
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, 6 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 (6 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Shallow bay flat (6 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (43 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Deep basin (81 ft) | Tungsten jig + spikes, Rattle spoon (small) |
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 24 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 | open water | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (24 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (24 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Break off the point (43 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 6 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 (6 ft) | Spinnerbait, Chatterbait |
| Summer | 8 to 20 ft | dawn & dusk | Shallow bay flat (6 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Shallow bay flat (6 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 15 to 35 ft | midday | Break off the point (43 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 24 ft that scores prime in fall. 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 | open water | 1/16 oz jig + grub, Small inline spinner |
| Summer | 5 to 20 ft | dusk | Main-lake point (24 ft) | Ned rig (small), Marabou jig |
| Fall | 8 to 22 ft | midday | Main-lake point (24 ft) | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Deep basin (81 ft) | Tungsten jig + plastic, Small spoon + spike |
Come spring, look for pumpkinseed tight to the bank in 1 to 8 ft. They move out to 2 to 10 ft in summer and finish the year down in 6 to 18 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 6 ft that scores prime in spring. Best bite is the evening and early morning. A micro tube or a sponge spider (fly) is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 1 to 8 ft | midday & dusk | Shallow bay flat (6 ft) | Micro jig under a float, Tiny beetle-spin |
| Summer | 2 to 10 ft | dusk & dawn | Shallow bay flat (6 ft) | Micro tube, Sponge spider (fly) |
| Fall | 4 to 14 ft | dusk & dawn | Shallow bay flat (6 ft) | Micro jig + waxworm, Small spoon tipped |
| Winter | 6 to 18 ft | dawn | Shallow bay flat (6 ft) | Tungsten ice jig + plastic, Tiny spoon |
Start shallow in spring: brown bullhead sit in 2 to 8 ft that time of year. Warm water sends them out to 3 to 12 ft; cold water stacks them in 10 to 25 ft. Top water on the chart: Shallow bay flat, a weed flat in the 6 ft range, prime in spring. Fish it in after dark and the evening and you'll meet the bite.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | dusk & night | Shallow bay flat (6 ft) | |
| Summer | 3 to 12 ft | night & dusk | Shallow bay flat (6 ft) | |
| Fall | 5 to 15 ft | dusk | Shallow bay flat (6 ft) | |
| Winter | 10 to 25 ft | midday | Deep basin (81 ft) |
6 pieces of structure are mapped here — Deep basin, around 81 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 Rock Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Rock Lake is about 95 ft (29 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.
Anglers target yellow perch, smallmouth bass, largemouth bass, rock bass, pumpkinseed, brown bullhead on Rock Lake.
Shallow bay flat is the top-rated area: a weed flat in about 6 ft of water that rates prime for yellow perch in spring. The map above holds the full rated-spot list for every species and season.
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.
Fishing on Rock 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.
Lake of the Hills 1 mi · Silver Lake 4 mi · Rainbow Lake 4 mi · Farren Lake 4 mi · Little Silver Lake 4 mi · Crow Lake 5 mi · O'Brien Lake 5 mi · McGowan Lake 6 mi · Sharbot Lake 6 mi · Bobs Lake 6 mi · Crosby Lake 7 mi · Christie Lake 7 mi
See how Rock Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best yellow perch lakes in Ontario · best rock bass lakes in Ontario
More water nearby: Frontenac County fishing maps (127 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.