This story starts 15 million years ago with a freshwater aquatic predator that dominated North America’s primitive rivers. Fossils of that Miocene Epoch monster are indistinguishable from the modern flathead catfish.

The perfect predator still plies the waters of the Mississippi River system, with the eastern edge of the flathead’s native range stretching to the Allegheny and Monongahela rivers. Despite this year’s wet weather, Pennsylvania anglers who target flatheads are reporting a banner year.

On the Susquehanna River — part of the flathead’s expanded range where the Pennsylvania Fish and Boat Commission considers it an invasive predator — a state record was set in April: 50 pounds, 7 ounces (45¼ inches, 31¼ inch girth). Jeff Bonawitz of Lancaster County said he caught and released several 30-pounders before rigging his biggest bait and setting the hook on nearly 4 feet of muscle that gave him a 25-minute fight.

Closer to home, catches of flatheads in the 40-inch range were posted with some regularity in Fishing Report this summer. Big catfish were caught in the Allegheny, Monongahela and Ohio rivers. Though preferences and techniques vary, these anglers agree on one thing.

“To catch big catfish, you have to go after big catfish,” said Pierce Valentin of Mount Washington.

Mr. Valentin and his brother, Hunter, are big fish hunters. From a 1940s,13-foot aluminum boat with a 7-horsepower outboard, they target flatheads on the Ohio River. They use medium-heavy rods strung with 60-pound line attached with a swivel to 12-18 inches of 50-pound leader. A 3-4 ounce Carolina rigged sinker is slid on and a No. 5-8 circle hook is tied on the end.

“I use three rods and my brother has two rods,” said Mr. Valentin. “I always try to have one or two [rigged with] cut-bait and the others with live bait. We like to use live bluegills — palm size, the bigger the better.”

In Pittsburgh waters, it’s easy to find the industrial structure the flatheads prefer, said Mr. Valentin.

“They like bridge pylons, log jams, anything that creates an eddy with slow moving water,” he said. “At least 10 feet deep. Lately we’ve been fishing at 20 feet. First light is really good. We get there early in the morning and fish 2 a.m. to 10 a.m., and then 6 p.m. to midnight.”

Big flatheads are powerful, vicious predators.

“First it comes in for the kill strike,” Mr. Valentin said. “Then it comes back around and takes the fish. Then it runs with it. If you set the hook right away, you’ll pull the bait out of its mouth. It’s very important to make sure to wait until the line is being pulled out as the fish begins to run with it. It never happens right away, but could take 2 to 5 minutes.”

Dave Hawk of Ross alerted Fishing Report in August when he caught two flatheads — 39 inches and 43 inches — on the Ohio River within 24 hours.

“Flathead are a very unique fish,” he said. “When it comes to finding these fish, it can be tricky. … Once the spawn kicks in they seem to spread out all over, making them harder to target, especially for the shore fisherman. Most of the summer you’ll need to find the deeper holes they lurk in, usually around 20-40 feet of water. In September and October … they will prepare for the colder months.”

Mr. Hawk’s “very traditional” setup starts with a 9-foot spinning rod, 30-pound Whisker Seeker monofilament line, a no-slip 2-8 ounce sinker and a swivel. He then ties on 12-18 inches of 40-50 pound mono leader and Gamakatsu circle hooks in 8/O to 5/O.

“I’ve tested every possible scenario from deep to shallow water, rough water, hot days, cold days, daylight fishing, night fishing, different current breaks, casting into eddies, high structure, no structure. All have produced fish,” he said.

James Swearingen of Windgap generated a social media buzz when he sent Fishing Report his photo of a 40-inch, 35½-pound flathead catfish caught and released on the Ohio River on Aug. 11.

He walked to his spot carrying 9-foot medium-heavy weight American Spirit Night Sticks with 6500 series and 7000 series Abu Garcia Ambassadeur reels.

“For my main line I use 30-pound test Slime Line monofilament by Catch the Fever,” he said. “I run that to an 80-pound barrel swivel that I use to connect my main line to my leader, a clear 50-pound test Berkeley Big Game monofilament. For hooks I run a variety of sizes for different presentations. When I use cut bait I use 4/0 to 6/0 Gamakatsu Octopus hooks, and for live bait I like to run anywhere from 7/0 to 10/0 [hooks] depending on bait size.

“I usually use weight ranging from 2 to 6 ounces. It all depends on the structure and current we are fishing at that time. The live baits I like to use for flatheads are bluegills or suckers, dead and alive. Remember it’s always good to be versatile.”

He caught the 40-incher from shore around dusk with an eddy swirling on the surface.

“I know big fish prefer slack water,” he said. “My bait-clicker started going. I knew it was a solid fish because of the long steady pull on the bait-clicker, synonymous with a quality flathead. After letting the line go out for 10-15 seconds, I turned off the bait-clicker and set the hook.”

Luke Wholey, owner of Luke Wholey’s Wild Alaskan Grille in the Strip District, is known as a hunter of big fish. He and nephew Bobby Wholey, 11, of New York placed second with a 39-inch flathead in the annual Allegheny River Tournament run by Lock 3 Bait and Tackle in Cheswick.

“It’s been a pretty good year for flatheads for a lot of guys,” he said. “The increased catches [are because] more people are targeting the big cats, and anglers’ techniques are improving. The big cats have always been in the river and catchable during the right conditions.”

This article was courtesy of John Hayes who writes for the Pittsburgh Post Gazette.