Concrete revetment attracts big flatheads, especially old blown-up dams. This type of structure is found on big-river navigation systems along with banks covered with riprap. Look for them near dams, bridges and causeways where engineers place the rocks to prevent erosion. The best fishing areas tend to be those where a small section of the bank has slightly different cover or structure than the rest of a long, look-alike stretch of riprap. For example, a submered tree or log may attract catfish. Other times, a difference in the rocks does the trick. Watch for big boulders changing to smaller rocks or slides of rocks creating underwater points. Start downstream and troll slowly upstream parallel to the bank, watching the sonar screen for the ups and downs of buckled-up revetment slabs. Then, when you find a hole and feel like the boat is directly over it, pick out a reference spot on the bank. You can now motor upstream and anchor the boat casting distance away from the hole. Cast your bait to the rocks in these areas and fish it right on bottom. If you haven't had a bite after 15 to 20 minutes, troll up the bank until you find another likely spot and anchor again. Continue doing this, working your way upstream and fishing first one hole and then another. Submerged timber, such as fallen trees, log jams, and stumps have produced good for me. The best trees are in locations that allow catfish easy movement between shallow and deep water. Look for fallen and flooded trees along channel drop-offs, underwater humps and holes, the edges of shallow flats and other fast-breaking structure. My favorite hotspot is where several trees have washed out and toppled into the water on an outside stream bend. Outside bends usually have deep pockets of water adjacent to a channel break. Heavy line and tackle are a must for this type of fishing. Overkill is welcomed in this type of structure to prevent short-comings as much as possible. You don't want to let a hooked fish diddle around in the cover. Get it out of there fast if you can, and let it do its fighting closer to the boat or shore. A good quality long rod gives you a fighting advantage and allows you to fish dense cover better, where casting is virtually impossible. Tip: set your drag just barely below your line's breaking point. You don't want a big brush pile cat peeling off any more line than necessary, or you'll be hung up in an instant. Any standard catfish bait can be used, but for tree cats, I prefer cut shad or skipjack. Big cats love cut bait, and dead baits don't get tangled like live baits. I thread a chunk about two inches square on a 7/0 or larger circle hook. Due to river current, I like using short leaders,(6-10 inches from the slip sinker),unless there is little to no current then I don't use any weight.