Diet is a main difference between flathead and blue cats. After achieving 10 inches in length, flatheads turn to live fish for 99 percent of their diet. While blues do eat fish, they also eat invertebrates and other foods.

Both live in similar waters, preferring rivers or river-related waters. That’s good for Mississippi, since those make up basically all of our public waters -- free-flowing rivers or streams, impoundments on rivers or streams, or oxbows formed when the rivers change course. It also explains role of the Mississippi River and its tributaries as the providers of most of the giant yellow cats and blues reported each year.

“Without a doubt, the Mississippi River is one of the world’s greatest catfish waterways,” said Sidney Montgomery, a lifelong fisherman on the river and a former river keeper on the Big Muddy. “Yet, it is one of the most underutilized fisheries -- at least, it is here in Mississippi.

“When it comes to catfish, there is a never-ending supply in the river. You can catch hundreds of what we call ‘keepers.’ Or you can target the true trophy catfish like the big flatheads and blues. I have never caught one that big -- but I know I’ve had 100-pounders on that I couldn’t deal with.”

What Montgomery likes most about Mississippi River cats is that varying styles of fishing can work on them. “Tightlining, trotlining, jugging and all that,” he said, “I love it all and do it all. But nothing beats hooking up with one of those giants on a hook and line and rod and reel.”

His favorite tactic: fishing the river on a rapid fall from high levels during the late spring or early summer. “When the river falls, it pulls a lot of the fresh, clear water out of the connected oxbows and sloughs and I love to find where that clear water is mixing with the muddy water blowing down the river,” he explained. “The perfect situation is finding where the clean-muddy line is mixing as it passes over a point or a long bar. That’s where I like to anchor and cast downcurrent with cut shad and wait for a big old blue to come along. It usually won’t take long: It’s going to happen -- and chances are it’s going to happen fast and regular.

“When I want a challenge, I move to find a deep hole formed by eddy currents whipping around a jetty. Not just any deep hole, but one loaded with long jams with water rising from a depth of 80 or 100 feet up to like 25 or 30 feet. I run that whole area with my graph, and it’s unbelievable the number of big arches that it will show.”

Each of those arches on the depthfinder is a big flathead catfish. The ones Montgomery is interested in aren’t the ones suspended, but the cats close to the bottom.

The angler marks the area and then goes off to catch some fresh live skipjack shad or small white bass for bait. He then returns, puts a whole live bait on a hook and drops it down to those bottom-holding fish. All he wants is one bite.

“It’s kind of like yellowfin tuna fishing,” he mused. “One is enough, and two is too darned many -- because you can’t handle it!”