Anglers sing the praises of man-made rock structure in regions where soft-bottomed reservoirs offer little or no natural walleye spawning habitat. Rock riprap along the faces of dams and causeways creates what Mother Nature forgot to provide: suitable hard-bottomed spawning habitat washed by current, perfect for the deposition and oxygenation of walleye eggs, safe from predators until the fry hatch and scatter into the open-water surface layers of the main lake. This is the ideal spring fish attractor once water temperatures approach the 42F to 55F range.
Rods: 7- to 9-foot spinning or casting rods on outside lines and 5 1/2- to 6-foot rods for inside lines.
Reels: medium-capacity spinning or baitcasting reels.
Line: 10-pound-test abrasion-resistant monofilament.
The key to effective trolling is to stagger lines and lures at different depths to cover the sloping face of the dam or causeway. To best accomplish this, select lures that run at a range of diving depths. Troll the shallowest versions closest to the dam, switching to deeper-running baits farther out. Use different rod lengths to spread lines on the same side of the boat. For example, on the line closest to the dam, longline troll a shallow-running minnow imitator on a 7- to 9-foot rod. Then use a slightly deeper-running lure on the same side of the boat on a 5 1/2- to 6-foot rod. Do the same on the opposite side of the boat, but consider the slope of the rock face and the lure's running depth to reach near or occasionally bounce bottom.
When darkness falls, fish move shallow. Use an electric or small outboard motor to move just fast enough to wobble your crankbaits. Proceed parallel along the dam face in a straight path; weaving is unnecessary and usually counterproductive, since it takes baits over open water instead of skimming the face of the rocks. Occasional lure contact with the rocks is fine, but avoid pounding lures-sooner or later you'll snag. Pump handheld rods occasionally to add a stop-and-go action to lures, making them appear vulnerable or wounded to further enhance their attractiveness to walleyes.