Catfish Week: Training Your Way to Big River Catfish

Stan was a river rat on the upper Mississippi River. He was legendary for catching catfish in spring, summer, and fall. It didn’t matter if the river was high and wild, or so low sandbars were exposed, Stan caught catfish. Mostly channel cats, but he could catch flatheads when he was in the mood. If blue cats had been an option on that stretch of river, he would have caught them, too.

I eventually made my way into his good graces and got an invitation to spend time with him. My goal was to learn from him, if not the locations of his secret fishing holes, then to at least pick up ideas on what sort of areas were most productive for him.

He told me to meet him at a public access near Belleview, Iowa. I found him sitting on the tailgate of his 1980s-era Ford F-150. The butts of a couple battered Ugly Stik rods with Abu Garcia baitcasting reels were nested in one of two white plastic 5-gallon buckets at his feet. We exchanged pleasantries and he eventually said, “Let’s go fishing.” I stepped toward the passenger side of his truck, but he picked up his buckets and ambled toward the river across the cropped lawn of the public area. He picked his way down some jumbled riprap to where a wing dam met the riprapped shore. In minutes we were rigged with Sonny’s Super Sticky dipbait, and soon catching 3- to 5-pound channel cats.

I was more than happy to sit and catch cats, but pestered him with questions about where else he fished—where did he go when he wanted flatheads, where did he fish when the river got high, did he ever fish from a boat? His answers were generic, often little more than a vague gesture with his hand and arm toward the river. I thought he was being cagey, and I kept pushing for details, until he finally arthritically turned his upper body toward me, squinted, and declared, “This is my secret spot for catfish. These wing dams and this stretch of riprap. The current’s right and there’s plenty of structure in this area so there are cats around here no matter how high or how low the river is, or what time of year it is. All of that,” he said, pointing the broad expanse of the Mississippi flowing in front of us, “is just water.”

Finding the Best Water

Stan was right. We can side-scan, we can read topo maps, and we can study surface currents, all in the name of finding catfish, but it all comes down to current. Places where something in the water affects the current—speeds it up, slows it down, or somehow alters it. The trick is to identify what, where, and when those changes in current occur. Wing dams, retaining walls, and other man-made structures are the “what” and “where,” and the “when” is anytime you want to catch fish.

“Fish want a certain water velocity when they’re resting, and different velocities when they’re feeding,” says Kirk Hansen, fishery biologist with the Iowa Department of Natural Resources. “Wing dams and manmade structures in rivers produce changes in velocity at different places along each structure, and at different water levels. The currents cats look for are probably somewhere around a set of wing dams no matter what the water level is. It’s just a matter of knowing which structures to fish and where to fish on them at those different water levels.”

The U.S. Army Corps of Engineers refers to wing dams, wing dikes, chevron dikes, and the dozens of other man-made structures they install in rivers as “training structures” because those structures “train” the currents in rivers to flow in specific directions. Because the structures change the direction and velocity of the current, it could be said that the structures also “train” catfish to congregate in specific locations depending on how currents move around those artificial structures.

Wing dams that protrude out into a river’s channel at a right angle to the shoreline provide multi-purpose habitat for all species of catfish. Some wing dams are designed to always be above water level except during floods. Others exist below the surface at normal water levels, invisible except during extreme droughts. Many wing dams are located on outside bends of rivers, designed to deflect the main current away from the bank and toward the center channel. Others are placed on the inside of bends to force currents out toward the main channel. The interaction between wing dams and currents tends to produce troughs, holes, and flats frequently used by all species of catfish.

In general, currents strike and then slide along the upriver side of wing dams back toward the center of the river, creating a trough parallel to the length of the structure. As the current rounds the tip of the structure, the confluence of the water sliding along the upriver side with unobstructed current flowing off the tip creates a hole just off the end of the structure. Depending on the strength of the current and the angle at which it strikes the wing dam, another trough or hole often develops on the backside of the structure. Backside holes and troughs are also common below submerged wing dams because currents push up and over the structures, increasing their velocity and creating turbulence that carves out the backside.

Some submerged wing dams have notches designed into their tops. “Biologists requested them,” says Joe Jordan, an environmental biologist with the Army Corps of Engineers and avid angler. “A notch adds more areas of altered velocity, and creates more eddies and areas of reduced current. That provides more opportunities for invertebrates and crustaceans, and on up the food chain. There generally is more biomass associated with notched wing dams than conventional wing dams. So, if you know there’s a notch in a wing dam, that’s a good place to fish.”

Anglers can predict where to find different species of catfish depending on current velocity around or over wing dams. Blue catfish aren’t bothered by strong currents, and often associate with deep holes off the tips of wing dams, most often where strong currents flow over the leading upper edge of those holes.

Flatheads like deep holes but prefer less current, so are often found over the edge of the major holes, or down in the bottom where currents are diffused. During low water when currents are mild, flatheads may patrol or lay in the bottom of troughs on the upper side of wing dams, ambushing prey moving against the dam with the current. Flatheads will also set up in deeper water on the downriver side of dams, and especially below any notches in submerged dams.

Channel catfish, on the other hand, favor milder current, and are often found in the bottom of troughs on the upriver side of wing dams, protected from the main current, in the bottom of holes at the tips of structures, and in deeper, protected water on the backside of wing dams.

As currents return to normal speed below structures, sediments drop out, creating broad flats of somewhat shallower water. “Everybody thinks deep water is the secret to catching big catfish, so everybody fishes the holes around wing dams,” says catfish guide Captain Ryan Casey, owner of ShowMe Catfishing Trophy Guide Service based in St. Louis. “I’ve had just as good of luck fishing flats downstream or between wing dams. Two of the biggest blues I’ve put in my boat came from less than 5 feet of water. One of them was a 105-pounder I caught out of 4 feet of water in winter a couple years ago. I always check big flats behind wing dams. I watch my side-imaging sonar. If I see a lot of big fish scattered across a flat pointed in various directions, they’re probably big carp or buffalo or rough fish. But if I see big fish on a flat that are all pointing upstream, they’re probably blue cats—big ones—and it’s time to put out baits.”

Casey mentioned fishing between wing dams, which brings up the topic of multiple wing dams. Wing dams are often constructed in sets of multiple structures spaced around the inner or outer perimeter of river bends. Catfish move up or downstream between wing dams depending on changes in water level and current.

“In low-water situations with slower current velocities, fish move to structures on the upper end of a series of wing dams,” Hansen says. “As river levels rise, current velocities increase and the fish tend to move to wing dams farther downstream, where the cumulative effect of the dams reduces the overall current.”

Wing dams on inside bends of rivers provide good examples of the fickle nature of rivers. The hydrodynamics are complex, but in general, when a river is falling, troughs on the upriver side of structures on inside bends are deepened. Troughs and holes on the downstream side tend to silt in. But when a river is rising, increased current velocity tends to silt in troughs and holes on the upstream side of structures and excavate the downriver side. The resultant increase or decrease in water depth influences how fish relate to those structures.

More Than One Way to Train

While training structures in smaller rivers are often limited to wing dams, larger rivers such as the lower Mississippi offer additional current-altering alternatives for catfish and anglers.

Weirs are W-shaped rock structures placed in main channels or associated with channels along outside bends. Depending on water level, the structures aren’t always visible to anglers but are well known to catfish.

“The Corps doesn’t use weirs in the Mississippi above Hannibal, Missouri,” Jordan says. “Weirs add a lot of changes to current and water velocity. We’ve seen strong increases in biodiversity associated with them, and biodiversity attracts gamefish like catfish.”

Weirs often have large, deep scour holes on their downstream side. Blue cat hunters who use navigation maps to locate a weir and then side-scan individual fish in holes associated with the weir can often “walk” baits to them and land monstrous blue cats from the lower Mississippi.

Chevron dikes are V-shaped structures with their closed end pointing upstream. In places where the Corps of Engineers has dredged bottom material to create islands, or where the Corps wants to preserve existing islands, chevron dikes are placed slightly upstream from the island to deflect current around the sides of the island.

“There are chevron dikes on Pool 18 on the Mississippi that are above water at normal pool,” Jordan says. “I see catfish guys fishing at the upstream point of those structures, in the area of slack water where the current is deciding if it’s going to go to the left or right of the structure. They’ll anchor above that area, and that lets them fish the eddy at the point as well as the current seams that go down each side of the structure.”

Reading Rivers

While shore anglers are limited to reading a river’s currents on the surface near training structures, there are indicators that reveal the intricacies of what’s going on below the surface.

It’s common during periods of high water, especially on big bends in rivers, to see a line of foam and small debris snaking downstream. That line of foam identifies the area of strongest current, technically known by the European term “thalweg line.” Foam and debris generally follow the path of highest flow, which creates the deepest channel and holes. It’s useful for shore anglers to note during floods how a river’s thalweg line, sometimes multiple thalweg lines, pass around or over wing dams and other man-made structures to identify where the deepest troughs and holes will be after waters recede.

Thalweg lines also reveal interesting information as they pass along the face of riprapped shorelines, also known as revetments. Many anglers assume the relatively uniform face of a riprapped shoreline is a fishing desert. Riprapped shorelines, especially where the riprap is made of fractured boulders, actually attract fish.

“Riprapped banks have all sorts of nooks and crannies that hold invertebrates and crustaceans,” Jordan says. “All the mini-points and pockets create eddies and back-currents, and even big flatheads will nestle into those areas of reduced current to ambush baitfish. Any place there’s an eddy on the surface next to a riprapped area, especially if there’s an area of back-current where the current is flowing upstream for a distance, are great places to hunt for catfish. Another thing that anglers often overlook is the junction where the base of the riprap meets the natural bottom of the river. That’s a transition from mud or sand to the rock of the riprap, running parallel to the shoreline. It’s a natural highway for fish moving up- or downriver.”

Shore anglers can also take tips from Casey, who uses shorelines between wing dams and above revetments to identify optimum places to fish. “The shoreline usually indicates what the bottom is like,” he says. “A sandy shoreline is good. A vegetated shoreline is okay, but what I look for between wing dams is a dark mud bank. Catfish like a good, firm mud bottom. If the bottom is sandy between wing dams, I’ve noticed that if the current is right, submerged sand dunes will develop. Some of them can be several feet high. An 80-pound blue cat can tuck behind a 2- or 3-foot bottom dune and be happy. Side-scanning and working those big flats can produce some big fish.”

Not every training structure on a big river holds catfish. “Some wing dams hold fish year in and year out,” Casey says. “Others rarely hold fish. The dikes may look the same to us, but there’s definitely something about some wing dams fish like, and other wing dams they don’t like. But any wing dam is a good place to start looking for catfish.”

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Dan Anderson, Bouton, Iowa, is an avid catfish angler and frequent contributor to In-Fisherman publications.

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