Lake depth chart
Today's read
Rating depth structure for largemouth bass.
Shared by DepthScout anglers. Exact spots stay private, always.
12-acre lake in Portage County, Wisconsin. The lake tops out around 25 ft. The chart is a model: real shoreline, published maximum depth, interpolated in between. A planning tool, never a navigation product. The rest of this page walks each species through its year, using the map's own scoring.
Drawn out, this is 12 acres of water rimmed by 0.6 miles of bank. A shoreline index of 1.2 says round and simple: fish relate to depth changes here, not shoreline features. 35% of the surface is littoral (under ~15 ft), per the model — cover, weeds and forage water. End to end it runs roughly 0.3 mi. You'll find it in Portage County. The nearest mapped water is Skunk Lake, 1 mi to the east.
Come spring, look for yellow perch tight to the bank in 3 to 12 ft. They move out to 8 to 25 ft in summer and finish the year down in 8 to 25 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 3 ft that scores prime in spring. Best bite is early morning. A drop-shot micro plastics or a small spoon tipped with worm is the honest summer answer here.
| 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 | 8 to 25 ft | dawn | Deep basin (21 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 8 to 25 ft | midday | Deep basin (21 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 8 to 25 ft | midday & dawn | Deep basin (21 ft) | Tungsten jig + spikes, Rattle spoon (small) |
The spring pattern is a shallow one: largemouth bass in 2 to 10 ft. Midsummer fish sit out in 8 to 20 ft before dropping to 8 to 25 ft for winter. The spot to know is Shallow bay flat, a weed flat in about 3 ft of water that rates prime for largemouth bass in spring. Plan around early morning and the evening in the warm months. Summer baits: a texas-rigged 10" worm or a deep-diving crankbait gets it done.
| 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 | Shoreline break (11 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Shallow bay flat (3 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 8 to 25 ft | midday | Shoreline break (11 ft) | Blade bait, Jigging spoon |
Start shallow in spring: crappie sit in 2 to 8 ft that time of year. Warm water sends them out to 10 to 25 ft; cold water stacks them in 8 to 25 ft. Top water on the chart: Deep basin, a deep basin in the 21 ft range, prime in winter. Fish it in early morning and the evening and you'll meet the bite. Throw a jig trolled/spider-rigged or a small crankbait (trolled) until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (3 ft) | 1/16 oz jig + tube, Curly-tail grub |
| Summer | 10 to 25 ft | dawn & dusk | Shoreline break (11 ft) | Jig trolled/spider-rigged, Small crankbait (trolled) |
| Fall | 8 to 20 ft | dawn | Shoreline break (11 ft) | Jig + minnow combo, Small swimbait (1.5-2") |
| Winter | 8 to 25 ft | midday | Deep basin (21 ft) | Tungsten jig + soft plastic, Tiny jigging spoon |
In spring, bluegill run shallow here, mostly 1 to 6 ft. Midsummer fish sit out in 4 to 15 ft before dropping to 10 to 25 ft for winter. Spring bluegill 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 small sponge spider (fly) or a micro tube jig most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 1 to 6 ft | midday & dusk | Shallow bay flat (3 ft) | 1/32 oz jig + micro plastic, Tiny popper (evenings) |
| Summer | 4 to 15 ft | dawn & dusk | Shallow bay flat (3 ft) | Small sponge spider (fly), Micro tube jig |
| Fall | 6 to 18 ft | midday | Shoreline break (11 ft) | Micro jig + waxworm, Small spoon tipped |
| Winter | 10 to 25 ft | midday | Deep basin (21 ft) | Tungsten ice jig + plastic, Tiny spoon |
Structure-wise the chart holds 4 features, led in depth by Deep basin at roughly 21 ft.
Season dates, license requirements, and size and bag limits for Wisconsin waters are set by the Wisconsin DNR — and special regulations can apply to Thorn Lake specifically, so confirm the current rules before you fish.
Check the official Wisconsin fishing regulations →
Thorn Lake is about 25 ft (8 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, largemouth bass, crappie, bluegill on Thorn Lake. These come from the Wisconsin DNR's per-lake fish listing; where the DNR lists a group (panfish, catfish, trout) the specific species are resolved from Wisconsin's fish distribution by the lake's location, depth and habitat.
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. Open the map above to see every rated spot for each 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 Thorn Lake is regulated by the Wisconsin DNR. Check the official Wisconsin regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Skunk Lake 1 mi · Foster Lake 1 mi · Grenlie Lake 1 mi · Johnson Lake 2 mi · Marl Lake 2 mi · Sand Lake 3 mi · Amherst Millpond 3 mi · Gurholt Lake 4 mi · Meed Lake 4 mi · Lake Bingo 4 mi · Rollofson Lake 4 mi · Brekke Lake 5 mi
See how Thorn Lake stacks up: best largemouth bass lakes in Wisconsin · best crappie lakes in Wisconsin · best bluegill lakes in Wisconsin · best yellow perch lakes in Wisconsin
More water nearby: Portage County fishing maps (48 charts). Browse all Wisconsin 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.