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Rating depth structure for smallmouth bass.
Recent public catches load as you reach this section.
13,955-acre flowage near Mauston. The lake tops out around 35 ft. These contours are modeled — built from the real shoreline and the water's maximum depth — so read them as a guide, never as navigation. Here's the year, species by species, as the scoring engine sees it.
Traced from the shoreline, Castle Rock Flowage runs 14,719 acres with 127.2 miles of edge — 11 islands included. The 7.5 development index tells the story — a convoluted bank whose fishable edge far outruns the acreage. Roughly 76% of the water is 15 ft or less as modeled, the band where the food chain lives. The basin spans about 13.3 mi end to end and 7.3 mi across at its widest. You'll find it in Juneau County. Closest neighbour on DepthScout: Castle Rock Lake, 2 mi southwest of here.
Early season walleye use the shallows, holding in 4 to 15 ft. Expect a summer slide to 15 to 35 ft, then a winter hold in 11 to 35 ft. Put Little Yellow River inflow first on the milk run — an inflow / creek mouth near 4 ft that grades prime for spring. In summer the feeding windows fall in the evening and early morning. Tie on a crawler harness on bottom bouncer or a deep crankbait (trolled) and you're in the game.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Little Yellow River inflow (4 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Break off the point (16 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 11 to 35 ft chart-limited; documented 12 to 40 ft | dusk & night | Break off the point (16 ft) | Jigging rap, Jig + big minnow |
| Winter | 11 to 35 ft chart-limited; documented 20 to 40 ft | dusk & dawn | Deep basin (30 ft) | Jigging spoon + minnow head, Rattle bait |
Spring puts crappie in skinny water — 2 to 8 ft is the zone. Warm water sends them out to 10 to 25 ft; cold water stacks them in 15 to 35 ft. Old creek channel is the standout, a creek channel at roughly 18 ft, rated prime for fall crappie. Plan around early morning and the evening in the warm months. A jig trolled/spider-rigged or a small crankbait (trolled) covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (4 ft) | 1/16 oz jig + tube, Curly-tail grub |
| Summer | 10 to 25 ft | dawn & dusk | Old creek channel (18 ft) | Jig trolled/spider-rigged, Small crankbait (trolled) |
| Fall | 8 to 20 ft | dawn | Old creek channel (18 ft) | Jig + minnow combo, Small swimbait (1.5-2") |
| Winter | 15 to 35 ft | midday | Deep basin (30 ft) | Tungsten jig + soft plastic, Tiny jigging spoon |
Spring puts white bass & hybrids in skinny water — 3 to 15 ft is the zone. Warm water sends them out to 10 to 30 ft; cold water stacks them in 11 to 35 ft. Little Yellow River inflow is the standout, an inflow / creek mouth at roughly 4 ft, rated prime for spring white bass & hybrids. Plan around early morning and the evening in the warm months. A jigging spoon or a topwater (when schooling) covers the summer program.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 15 ft | midday & dawn | Little Yellow River inflow (4 ft) | Rooster tail / inline spinner, Curly-tail jig (white/chartreuse) |
| Summer | 10 to 30 ft | dawn & dusk | Main-lake point (9 ft) | Jigging spoon, Topwater (when schooling) |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (9 ft) | Small blade bait, Jigging spoon |
| Winter | 11 to 35 ft chart-limited; documented 20 to 40 ft | midday | Deep basin (30 ft) | Jigging spoon, Blade bait (vertical) |
In spring, channel catfish run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 8 to 25 ft before dropping to 11 to 35 ft for winter. Spring channel catfish concentrate at Little Yellow River inflow, a prime-rated inflow / creek mouth around 4 ft. Fish it in after dark and the evening and you'll meet the bite.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dusk | Little Yellow River inflow (4 ft) | |
| Summer | 8 to 25 ft | night & dusk | Old creek channel (18 ft) | |
| Fall | 10 to 30 ft | dusk | Old creek channel (18 ft) | |
| Winter | 11 to 35 ft chart-limited; documented 20 to 40 ft | midday | Deep basin (30 ft) |
Start shallow in spring: flathead catfish sit in 5 to 20 ft that time of year. Warm water sends them out to 8 to 30 ft; cold water stacks them in 11 to 35 ft. Top water on the chart: Deep basin, a deep basin in the 30 ft range, prime in fall. Fish it in after dark and the evening and you'll meet the bite.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 20 ft | night & dusk | Old creek channel (18 ft) | |
| Summer | 8 to 30 ft | night & dusk | Deep basin (30 ft) | |
| Fall | 10 to 35 ft | night & dusk | Deep basin (30 ft) | |
| Winter | 11 to 35 ft chart-limited; documented 20 to 45 ft | midday | Deep basin (30 ft) |
Spring puts smallmouth bass in skinny water — 3 to 12 ft is the zone. Warm water sends them out to 10 to 30 ft; cold water stacks them in 11 to 35 ft. Rock reef is the standout, a rock pile at roughly 7 ft, rated prime for spring smallmouth bass. Plan around early morning and the evening in the warm months. A drop shot (goby/minnow) or a ned rig covers the summer program.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dawn & dusk | Rock reef (7 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (16 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (9 ft) | Jerkbait, Blade bait |
| Winter | 11 to 35 ft chart-limited; documented 20 to 45 ft | midday | Break off the point (16 ft) | Blade bait, Hair jig |
Castle Rock Flowage also holds bluegill (4 to 15 ft in summer), freshwater drum (8 to 30 ft in summer). Pick any of them on the map above for rated spots and bait picks.
18 pieces of structure are mapped here — Deep basin, around 30 ft, is the deepest of them.
Access data: Wisconsin DNR - Boat Access Sites, Shore Fishing Sites, and DNR Parking Lots; Wisconsin DNR - Public Access Lands Shoreline Geometry; Wisconsin DNR - Public Access Lands Shoreline Geometry; Wisconsin DNR - Public Access Lands Shoreline Geometry; Wisconsin DNR - Public Access Lands Shoreline Geometry. 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 Castle Rock Flowage specifically, so confirm the current rules before you fish.
Check the official Wisconsin fishing regulations →
Castle Rock Flowage is about 35 ft (11 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, crappie, white bass & hybrids, channel catfish, flathead catfish, smallmouth bass, bluegill, freshwater drum on Castle Rock Flowage.
Little Yellow River inflow is the top-rated area: an inflow / creek mouth in about 4 ft of water that rates prime for walleye in spring. Open the map above to see every rated spot for each 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 Castle Rock Flowage 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.
Castle Rock Lake 2 mi · Friendship Lake (Millpond) 8 mi · Big Roche A Cri Lake 10 mi · Easton Lake 12 mi · Rynearson Flowage No. 1 12 mi · Decorah Lake 12 mi · Petenwell Flowage 14 mi · Patrick Lake 16 mi · Sprague-Mather Flowage 16 mi · Eagle Nest Flowage (Potters) 17 mi · McGinnis Lake 18 mi · Arrowhead Lake (Manchester) 18 mi
See how Castle Rock Flowage stacks up: best smallmouth bass lakes in Wisconsin · best walleye lakes in Wisconsin · best crappie lakes in Wisconsin · best bluegill lakes in Wisconsin
More water nearby: Juneau County fishing maps (13 charts). Browse all Wisconsin fishing maps. 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.