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Rating depth structure for largemouth bass.
Shared by DepthScout anglers. Exact spots stay private, always.
144-acre lake in Iron County, Wisconsin. The lake tops out around 33 ft. Contours on this water are modeled from its actual shoreline and max depth. Good for finding likely water, never for navigation. What follows comes from the same scoring engine that paints the spots above.
The drawn water covers 144 acres wrapped in 3.1 miles of bank. With a 1.9 development index there's bank structure worth casting at, in moderation. Littoral water — the productive band under ~15 ft — makes up 74% of this chart, as modeled. Tip to tip the water measures near 1.1 mi with a 0.4-mi widest point. Iron County claims this one. Its nearest charted neighbour, San Domingo Lake, is 1 mi to the south.
In spring, walleye run shallow here, mostly 4 to 15 ft. Summer pushes them deeper, 10 to 33 ft, and winter fish settle into 10 to 33 ft. Break off the point is the standout, a drop-off at roughly 15 ft, rated prime for fall walleye. Time it for the evening and early morning. You won't need more than a crawler harness on bottom bouncer or a deep crankbait (trolled) most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (8 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 10 to 33 ft | dusk & dawn | Break off the point (15 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 10 to 33 ft | dusk & night | Break off the point (15 ft) | Jigging rap, Jig + big minnow |
| Winter | 10 to 33 ft | dusk & dawn | Deep basin (28 ft) | Jigging spoon + minnow head, Rattle bait |
The spring pattern is a shallow one: yellow perch in 3 to 12 ft. As the season builds they drop to 10 to 30 ft, wintering in 10 to 33 ft. Top water on the chart: Shallow bay flat, a weed flat in the 4 ft range, prime in spring. Time it for early morning. Summer baits: a drop-shot micro plastics or a small spoon tipped with worm gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (4 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Deep basin (28 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 10 to 33 ft | midday | Deep basin (28 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 10 to 33 ft | midday & dawn | Deep basin (28 ft) | Tungsten jig + spikes, Rattle spoon (small) |
When the water first warms, northern pike slide up into 2 to 8 ft. By summer they slide out to 8 to 20 ft, and by winter most fish are in 5 to 15 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 4 ft that scores prime in spring. In summer the feeding windows fall in early morning and the evening. Keep a bucktail or a weedless spoon over cabbage rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (4 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (15 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (15 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (4 ft) | Tip-ups, Large jigging spoon |
Come spring, look for muskellunge 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 10 to 33 ft. If you only fish one area, make it Break off the point: a drop-off around 15 ft that scores prime in fall. Best bite is the evening and early morning. A double-10 bucktail or a topwater (walk-the-dog / creeper) is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dusk | Shallow bay flat (4 ft) | Smaller bucktail (#8 blades), 6" glide bait |
| Summer | 8 to 25 ft | dusk & dawn | Main-lake point (8 ft) | Double-10 bucktail, Topwater (walk-the-dog / creeper) |
| Fall | 8 to 30 ft | midday & dusk | Break off the point (15 ft) | Big rubber (Bull Dawg style), 10"+ glide bait |
| Winter | 10 to 33 ft | midday | Deep basin (28 ft) | Large rubber, crawled slow |
When the water first warms, smallmouth bass slide up into 3 to 12 ft. By summer they slide out to 10 to 30 ft, and by winter most fish are in 10 to 33 ft. If you only fish one area, make it Main-lake point: a point around 8 ft that scores prime in fall. In summer the feeding windows fall in early morning and the evening. Keep a drop shot (goby/minnow) or a ned rig rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Main-lake point (8 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (15 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (8 ft) | Jerkbait, Blade bait |
| Winter | 10 to 33 ft | midday | Break off the point (15 ft) | Blade bait, Hair jig |
Come spring, look for largemouth bass tight to the bank in 2 to 10 ft. Expect a summer slide to 8 to 20 ft, then a winter hold in 10 to 33 ft. Start at Shallow bay flat. It's a weed flat holding about 4 ft of water and rates prime come spring. Prime time lands in early morning and the evening. A texas-rigged 10" worm or a deep-diving crankbait is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | dawn & dusk | Shallow bay flat (4 ft) | Spinnerbait, Chatterbait |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (15 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Main-lake point (8 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 10 to 33 ft | midday | Break off the point (15 ft) | Blade bait, Jigging spoon |
Grand Portage Lake also holds crappie (10 to 25 ft in summer), bluegill (4 to 15 ft in summer), pumpkinseed (2 to 10 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Structure-wise the chart holds 6 features, led in depth by Deep basin at roughly 28 ft.
Access data: Wisconsin DNR - Boat Access Sites, Shore Fishing Sites, and DNR Parking Lots. Confirm conditions and fees locally before you launch.
Season dates, license requirements, and size and bag limits for Wisconsin waters are set by the Wisconsin DNR — and special regulations can apply to Grand Portage Lake specifically, so confirm the current rules before you fish.
Check the official Wisconsin fishing regulations →
Grand Portage Lake is about 33 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.
Anglers target walleye, yellow perch, northern pike, muskellunge, smallmouth bass, largemouth bass, crappie, bluegill, pumpkinseed on Grand Portage 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.
Break off the point is the top-rated area: a drop-off in about 15 ft of water that rates prime for walleye in fall. Every other rated spot, per species and season, is on the map above.
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 Grand Portage 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.
San Domingo Lake 1 mi · Echo Lake 1 mi · Martha Lake 1 mi · Mercer Lake 1 mi · Bluegill Lake 1 mi · Little Martha Lake 1 mi · Rice Lake 1 mi · Lake Tahoe 2 mi · Kinder Lake 2 mi · Brush Lake 2 mi · Payment Lake 2 mi · Net Lake 2 mi
See how Grand Portage Lake stacks up: best largemouth bass lakes in Wisconsin · best smallmouth bass lakes in Wisconsin · best walleye lakes in Wisconsin · best northern pike lakes in Wisconsin
More water nearby: Iron County fishing maps (158 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.