Castle Rock Flowage was constructed by the Wisconsin River Power Company to work in cooperation with the Petenwell Flowage, located just up-river. Castle Rock provides hydroelectric power generation, flood control and recreation, with Buckhorn State Park and an adjoining wildlife area forming an 8,190-acre peninsula dividing the lake.
Black and white buoys have been placed to mark safe boating channels. The mouth of Little Roche a Cri Creek, the Wisconsin River north of the railroad bridge, and the entrance to the harbor at Castle Rock County Park all have buoys.
Due to its size, the main basin of the flowage can become extremely rough in a short period of time. Be aware of changing weather and wind conditions. Ice conditions also can be extremely dangerous throughout winter. Changing water levels, pressure ridges and flowing water from the Yellow and Wisconsin rivers often create hazardous ice. Check with local experts before venturing out onto the ice.
Approximately 2,500 large fingerling (7 to 9 inches) muskie are stocked annually into Castle Rock Flowage. The muskie population is maintained by these stockings. Lake sturgeon have been stocked throughout the Wisconsin River, including Castle Rock Flowage, in attempts to re-establish this species.
The walleye population remains stable despite a continuous open season and high angling pressure. An abundant forage base and consistent natural reproduction keeps this population healthy.
Interactive Lake Map
Here are some tips for locating and catching fish on Castle Rock Flowage:
- Spring walleye anglers concentrate efforts on the Wisconsin River below the Castle Rock dam, below the Necedah dam on the Yellow River and the Buckhorn Bridge area. Walleye on the lower end of the lake will utilize rock and gravel shoreline areas to spawn during spring.
- Smallmouth bass will relate primarily to riprap and rock structure throughout most of the open water season. The East Dike is known for producing good smallmouth bass fishing. Soft plastics including worms, craws, tubes and senkos will consistently produce. Choose baits in crayfish or pumpkinseed colors.
- Largemouth bass can occasionally be caught while trolling crankbaits for walleye. During early summer and before storm events, topwater baits will produce some exciting action. Pop-Rs and Zara Spooks in firetiger-pattern or other bright patterns should be used.
- Larger crappie will leave the shallows after spawning and will suspend along old river channels and stump fields found in the main lake. Summer crappie will follow forage and quality electronics are needed to locate the suspended crappie. Slip bobber rigs and tube jigs will produce at this period. Trolling with #5 Shad Raps will occasionally produce suspended crappie.
- During spring and fall, white bass follow similar migrations as walleye. The Wisconsin and Yellow rivers attract many white bass, usually in late April and early May. Spawning white bass can be found near sand/gravel drop offs. At this time, small in-line spinners and jig/minnow combinations will produce the most fish.