Idaho's monster fish: Lures in ‘ugly spots’ will catch an otherworldly flathead catfish

Editor’s note: The 2017 Idaho Outdoors fishing guide cover story was on some of the biggest, baddest fish in Idaho — and the anglers who pursue them. Here is the column introducing the series.

Today: Flathead catfish

Previously: Tiger muskies, Mackinaw trout, Chinook salmon

Coming up: White sturgeon (Thursday)

FLATHEAD CATFISH

Where to catch them: Snake River, Brownlee Reservoir, Weiser River.

Recommended gear: 7-foot medium-heavy rod and a large spinning or bait-casting reel spooled with 30-pound braided line (fluorocarbon leader recommended in clearer water).

What to use: Fresh cut bait on a large circle hook or big, deep-diving crankbaits and swimbaits.

State record: 58.5 pounds, caught by J. Newberry and K. McCormick in 1994.

Catch-and-release record: 34.5 inches, caught by Hope Stratton in 2016.

Featured monster hunter: Caleb Nichols, Boise.

They roam along the river bottom, hiding in underwater caves and root tangles as they wait for an unsuspecting meal to swim by.

They rarely visit the surface, and when they do, it’s like something out of a sci-fi movie. We are talking about the massive and otherworldly flathead catfish — one of Idaho’s most proficient ambush predators.

Boise angler Caleb Nichols has been catching catfish his whole life. But he never bumped into a flathead until six years ago.

“My dad and I had boated thousands of channel cats, but we never hooked up with a flathead,” Nichols said. “One time at Brownlee, we got some advice on where to go and what to use. Within 30 minutes, my old man pulled up a 28-pounder! We’ve been going after them ever since.”

Flatheads routinely reach lengths of 3 feet or more, with the largest specimens weighing more than 50 pounds. Big flatheads are rarer and harder to entice than their smaller cousins. They can be found throughout the Snake River system, but most flathead anglers focus on Brownlee Reservoir and the nearby stretches of the Snake.

Whereas channel and bullhead catfish readily munch on night crawlers, chicken livers and prepared catfish doughs, flatheads prefer to feast on smaller fish. You might occasionally hook one on traditional baits, but to really hone in on flatheads, you have to appeal to their aggressive nature.

“They pretty much hide up in a hole and wait for a chance to attack,” Nichols said. “They are so highly predatory, anything that looks like a meal will get these gluttonous beasts to come out and bite.”

In many states, anglers fish for flatheads with live fish. That’s against Idaho regulations, so options are limited to dead fish or artificial lures. For bait, crappie and bluegill cut bait seem to work particularly well — the remains of the last batch of panfish you filleted should do the trick. Large crankbaits and swimbaits fished along the bottom can also be deadly. But flatheads thrive in heavy rock or wood cover, so be prepared to lose a few lures along the way.

“You can’t be afraid to put your lures in some ugly spots,” Nichols said. “If you’re not getting hung up from time to time, you’re probably not in a very productive spot.”

Flatheads are distinguished by their enormous heads and huge, gaping mouths, which they use to vacuum-suck in their prey. When you feel a bite, set the hook hard! Flatheads aren’t crazy fighters, but their sheer, head-shaking weight will give you a run for your money—and the payoff when you finally lay eyes on that big toad will be more than worth it.

“I’m always surprised by how big they are,” Nichols said. “It’s so much fun to see them come up. I’d say most of what we catch is in the 15-to-20-pound range, but I know that state record is swimming around out there somewhere.”

This story was originally published March 14, 2017 at 10:50 PM with the headline "Idaho's monster fish: Lures in ‘ugly spots’ will catch an otherworldly flathead catfish."