Bighorn River Tactics – Fishing with the Grass
Late summer and early fall on the Bighorn River bring a distinctive set of challenges and rewards for anglers willing to navigate its changing aquatic landscape. Lush weed beds that start their growth in late July and August heat reach their peak density, choking backwater channels and creating a complex maze of submerged vegetation. For the unprepared angler, this jungle can lead to constant foul-hooking and endless frustration; however, for those who learn to read the underwater terrain, these weed beds become the ultimate holding water for Big Bighorn trout.
Success in the weed-choked upper river starts with understanding how trout relate to these structural jungles. Rather than scattering randomly, resident brown and rainbow trout set up shop along distinct weed line seams where fast current drops into slower, weed-lined troughs. These narrow, current-swept channels act as natural conveyor belts, funneling dislodged scuds, sowbugs, and nymphs directly to waiting fish. Targeting these high-probability lanes requires a surgical approach, focusing on micro-pockets and open gravel windows within the expansive vegetation where fish can comfortably ambush passing meals without having to fight heavy currents. Look for the color changes. Most notably ‘the dark water’ as I refer to it with my guests in the boat. These are the clean lanes where gravel is and the fish love it!
Tackling this environment demands specific adjustments to your rigging and presentation. Sometimes, I will utilize a shorter leader setup paired with a high-floating balloon to maintain precise control over your drift, while placing targeted split shot well above your flies prevents your rig from plunging straight into the moss. Fine-tuning your depth is an exacting science here. You want to be down in the zone, but you have to be in the right zone!
The one good side to this grass growth is the tremendous amount of bugs that are hiding around them. This is the source for the famous ‘worm hatch’ we’ve seen on the lower river the past few years. You’ll find endless amounts of Scuds and Sowbugs as well.
Ultimately, mastering the weed beds of the Bighorn River in the late season separates casual floaters from consistently successful anglers. By shifting your focus to the narrow channels, tightening your drift mechanics, and respecting the subtle nuances of the river’s autumnal transition, you unlock access to some of the most aggressive and well-fed trout of the year. Embrace the weeds, refine your presentation, and experience the upper Bighorn at its technical, rewarding best.