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108-acre reservoir near Wisconsin. The lake tops out around 32 ft. The contours are modeled from the water's real shoreline and maximum depth. Treat them as a rough guide, and never use them for navigation. Here is how the season plays out for each species, straight from the data behind the map.
Spring walleye on Grandfather Flowage hold shallow, usually 4 to 15 ft. They move out to 10 to 32 ft in summer and finish the year down in 10 to 32 ft. The spot to know is Break off the point, a drop-off in about 14 ft of water that rates prime for walleye in fall. Plan around the evening and early morning in the warm months. Summer baits: a crawler harness on bottom bouncer or a deep crankbait (trolled) gets it done.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | 1/8 oz jig + minnow, Hair jig |
| Summer | 10 to 32 ft | dusk & dawn | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 10 to 32 ft | dusk & night | Jigging rap, Jig + big minnow |
| Winter | 10 to 32 ft | dusk & dawn | Jigging spoon + minnow head, Rattle bait |
Start shallow in spring: yellow perch sit in 3 to 12 ft that time of year. They move out to 10 to 30 ft in summer and finish the year down in 10 to 32 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 4 ft that scores prime in spring. Plan around early morning in the warm months. A drop-shot micro plastics or a small spoon tipped with worm covers the summer program.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 10 to 32 ft | midday | Jigging spoon (small), Perch rig / spreader |
| Winter | 10 to 32 ft | midday & dawn | Tungsten jig + spikes, Rattle spoon (small) |
Spring northern pike on Grandfather Flowage hold shallow, usually 2 to 8 ft. Summer pushes them deeper, 8 to 20 ft, and winter fish settle into 5 to 15 ft. The spot to know is Shallow bay flat, a weed flat in about 4 ft of water that rates prime for northern pike in spring. Best bite is early morning and the evening. Summer baits: a bucktail or a weedless spoon over cabbage gets it done.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Tip-ups, Large jigging spoon |
Spring muskellunge on Grandfather Flowage hold shallow, usually 3 to 12 ft. Summer pushes them deeper, 8 to 25 ft, and winter fish settle into 10 to 32 ft. If you only fish one area, make it Break off the point: a drop-off around 14 ft that scores prime in fall. Plan around the evening and early morning in the warm months. Tie on a double-10 bucktail or a topwater (walk-the-dog / creeper) and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 3 to 12 ft | dusk | Smaller bucktail (#8 blades), 6" glide bait |
| Summer | 8 to 25 ft | dusk & dawn | Double-10 bucktail, Topwater (walk-the-dog / creeper) |
| Fall | 8 to 30 ft | midday & dusk | Big rubber (Bull Dawg style), 10"+ glide bait |
| Winter | 10 to 32 ft | midday | Large rubber, crawled slow |
Spring smallmouth bass on Grandfather Flowage hold shallow, usually 3 to 12 ft. By summer they slide out to 10 to 30 ft, and by winter most fish are in 10 to 32 ft. If you only fish one area, make it Main-lake point: a point around 8 ft that scores prime in fall. Best bite is early morning and the evening. Summer baits: a drop shot (goby/minnow) or a ned rig gets it done.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Jerkbait, Blade bait |
| Winter | 10 to 32 ft | midday | Blade bait, Hair jig |
Spring largemouth bass on Grandfather Flowage hold shallow, usually 2 to 10 ft. They move out to 8 to 20 ft in summer and finish the year down in 10 to 32 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. Tie on a texas-rigged 10" worm or a deep-diving crankbait and you're in the game.
| Season | Depth | Best window | Go-to baits |
|---|---|---|---|
| Spring | 2 to 10 ft | dawn & dusk | Spinnerbait, Chatterbait |
| Summer | 8 to 20 ft | dawn & dusk | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 4 to 15 ft | midday & dawn | Squarebill crankbait (shad), Spinnerbait |
| Winter | 10 to 32 ft | midday | Blade bait, Jigging spoon |
Grandfather Flowage 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.
How deep is Grandfather Flowage?
Grandfather Flowage is about 32 ft 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.
What fish are in Grandfather Flowage?
Anglers target largemouth bass, smallmouth bass, walleye, northern pike, crappie, bluegill, muskellunge, yellow perch, pumpkinseed on Grandfather Flowage. 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.
Where is the best fishing spot on Grandfather Flowage?
Break off the point is the top-rated area: a drop-off in about 14 ft of water that rates prime for walleye in fall. Open the map above to see every rated spot for each species and season.
When is the best time to fish Grandfather Flowage?
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.
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See how Grandfather Flowage 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
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