An old timer with an 8-inch Buck Knife strapped to his belt once told me that mousing for trout was invented on the North Branch of Michigan's Au Sable River. Not long after brown trout were introduced there—shortly after the grayling were gone—an angler was field-testing some bass poppers he'd carved and accidentally discovered that these German fish were eager to eat after dark.
For the last 100 years, the wolverine state has been a nighttime mousing kingdom of sorts. Anglers elsewhere just don't have the compulsion Michiganders do to mirror the trout's nocturnal behavior during the latter half of summer. You might have ran into guys coming off a mousing trip at the boat ramp. Their skin as pale as moonlight. Still wearing yesterday's clothes, smelling strongly of 5-Hour Energy and brown trout, they zombie-shuffle out of the water as you're lashing 7X to your favorite trico pattern.
While you think you know the river well, these guys can fish it with their eyes closed. Just don't ask them to fish it with eyes open; as some have never actually seen it. They have no idea the beaver meadow is covered in wildflowers, only that their backcasts now and then pick up goldenrod. And every so often their blind stripping results in a chaotic strike.
Although the strikes are mean, hookup rates while mousing can be dismal. If you get ten hits, you're lucky to set the hook on five. Some guys think it's because the fish are just coming in for a taste test, or to stun the fly. Two years ago, after reading Paul Schullery's book The Rise, it occured to me that many mouse patterns are too buoyant. Fish don't eat like we do, they suck their meal in with a vortex of air. If they didn't release the suck, they would lose a lot of food as their bodies displaced water while moving forward. So a more buoyant fly not only resists the force of the suck, it moves away from the suck. It's a double whammy.
So I looked at the features of more successful mouse patterns I'd fished, and those that never really caught fish. The ones that really sucked all had one thing in common: They were crazy buoyant. One had triple-thick 3mm foam and a bass popper head. Yeah, it made noise when stripped, and antagonized what sounded like some really nice fish, but only a 40-inch musky would have had the lung capacity to suck it down.
There were two patterns that I preferred. The first was a rabbit-and-foam slider. Hookup rates with that fly were in the 50- to 70-percent range. The other was basically a Gartside Gurgler tied with rabbit and 4mm foam. I attribute that fly's success to how well it sounded coming through the water. It was like ringing the dinner bell.
So I decided I wanted a foam-free fly. It had to float well enough to produce a nice wake and, if wanted, make some noise on a hard strip. The result is the Otsego Mouse. Somehow, this fly does everything I want, and maybe more. It quivers through the water on a dead swing, all the while producing a distinct wake. Trim the head shape more aggressively—think, Taps Bug—and it splashes and pops with the best of them. Caveat: It eventually sinks. And I get about 30 to 45 minutes out of it before I need to switch flies.
Hookup rates are greater than 50 percent thanks to the fly's tendency to "stick." An easy way to test stick factor is to drop a fly in the water and, with your fingers spread out, move your hand underneath to scoop it. Move your hand at an equal rate of speed and you'll see differences among patterns of all types. A good comparison is the high-floating Catskill dry vs. the low-riding parachute. Parachutes outfish Catskill dries for a variety of reasons, but its great stick factor is often overlooked.
Until you've done it, you'll never understand what it's like out there in the vacuum of space. You can't relate to the feeling of floating through a forest in a drift boat, head arched back, watching the stream of stars flow overhead between the tree lines. It's about channeling your inner bat so you can determine how far your mouse just splatted off the opposite bank. It's about the surreal feeling of waiting for the moon to set. It's about the suspense of working a mouse down and across, while feeling completely vulnerable to those things-that-go-bump-in-the-night and raise the hairs on the back of your neck.
You're not after fish, you're after a fish. It's the brown you and your friends have never seen, and the one biologists tell you does not exist.
For step-by-step tying instructions for the Otsego Mouse, click here