Brown trout (salmo trutta) can be found in cool freshwater — think high latitudes and high altitudes — across the United States, Europe, New Zealand, and Asia. They are a favorite target of reelers around the globe, even supplanting the popularity of native brook trout in the U.S. once they were introduced in the late 19th century.
They come in all shapes and sizes, but the biggest tend to be the lake and sea run browns that live in large bodies of slackwater and migrate up rivers and streams to spawn. You can chase browns in any season, but if you’re hunting the big ones, there’s no better time than autumn.
The reason browns can get so big (40 lbs. plus) is that once they make it through a couple spawning seasons, they’re pretty much the top of the food chain. Brian Wise, a fly fishing guide in the Ozarks — home to some world-class brown trout fisheries — says, “Once a brown trout reaches a certain size, they become major meat eaters. These fish get very predacious (think musky here) and will literally eat fish that are half their size.”
Fly reelers recommend saltwater-sized fly rods, sinking lines, and oversized flies when chasing big browns.
“I am pretty stuck on the 9′ 8 wt. Sage Salt for my main streamer rod. It is aggressive, but easy to cast sinking lines. As for lines, I am pretty partial to the new Cortland Compact Sink series. I always have 3 Allen reels spooled in the boat at all times, one with a T3, one with a T6, and one with a T9,” says Wise.
Out in Logan, Utah, Andrew Engel chases big brown beasts when they get aggressive during the pre-spawn. He favors a Spey rod and casting a baitfish pattern with streamers at a 45-degree angle to the river. Closer to the spawn, he’ll switch up to an egg pattern when the trout are trying to drive out rivals to the gene pool.
Bigger browns are such voracious eaters that they’ll attack small mammals in the water. So, Engel will occasionally use a wooly bugger fly or even try a mouse pattern with his fly rig.
Brown trout don’t all have to be big trophies, though. Chelsea Baum has had luck hooking browns in the 12” to 16” slot on the Truckee River in California with a nymphing pattern.
Most fly reelers agree, however, that when you’re chasing browns, you’re probably going to be stripping and more than likely, using streamers.
If you’re using a spinning or baitcasting rig, you can sometimes get big browns to chase a crankbait. A well-placed salmon egg or wax worm can also agitate a brown into a strike.
Regardless of the kind of gear you’re using, try to avoid bright sun. Brown trout of all sizes can be shy of shadows — especially in low-water situations. And if you can cast without wading, stay on the banks so you don’t disturb the water.
Another thing you’ll want is the thinnest line or leader possible. If a brown trout — especially one that’s been around the block a few times — can see your line, you’re going to have a really long day on the river.