"Bighorn River Fishing Report: Stellar Early Fall Conditions and Hot Trout Action"

Big Horn, Montana anglers, this is Artificial Lure coming to you with your Friday, September 12th, 2025 fishing report—and it is shaping up to be another stellar early fall day out on the legendary Bighorn River. Let’s start with today’s conditions. The skies are mostly clear this morning, with a touch of haze from the lingering wildfire smoke spotted upriver near the Rosebud County area earlier this week according to local news updates. The high is expected to top out in the mid-70s with just a light westerly breeze—perfect for wetting a line without wrestling wind. Sunrise was at 6:41 AM and you’ve got daylight stretching until 7:29 PM, so there’s plenty of time to target the feeding windows. No tidal swings here, but water flows are steady, running a touch above the late-summer average. Guides along the Bighorn have noted the river holding steady with crisp, clear water—ideal for sight fishing those bigger browns and rainbows. No alerts on closures or hazards from the National Park Service, so access is as good as it gets for wading or floating. Now, let’s talk fish. The action’s been hot all week, with fly anglers reporting exceptional numbers. The Bighorn is still delivering classic late-summer fishing. According to local guide chatter and this week’s fishing boards, rainbows are stacked in the riffles and the browns are starting to get a little feisty as the nights cool off. The consistent report has most folks hitting double digits per rod by mid-afternoon—expect good numbers of healthy 14-19 inch rainbows and a few hefty browns cruising the undercuts. On the fly front, terrestrials are still the order of the day. Grasshopper imitations in light tan and olive have been the ticket, especially mid-morning into early afternoon when the sun is high. Ants and beetles are landing some wary fish tight to the banks. For nymphers, a two-fly rig with a sowbug or tan scud trailed by a zebra midge has been deadly in the deeper tailouts—most productive from late morning through dusk. A few caddis are still fluttering, so don’t be afraid to throw a size 16-18 Elk Hair Caddis if you see surface activity near sunset. Spin anglers, don’t feel left out. Panther Martin spinners in gold and black or small Rapalas imitating juvenile trout have been drawing aggressive takes in the runs and along drop-offs. As for bait, you’ll do best going artificial by regulation, but if you’re fishing the ponds and backwaters (check regs for each spot!), try nightcrawlers or single salmon eggs for a chance at those sneaky cutthroat and a mixed bag of panfish. Now, for the hot spots: - The Afterbay section continues to fish exceptionally well, especially around the 3 Mile Access—plenty of accessible gravel bars and classic deep runs. - Don’t overlook the stretch below Bighorn Access—word has it some slabs are holding tight to structure midday. - In town, don’t sleep on the backwaters and sloughs near Ok-A-Beh Marina for a bonus bite—especially if you’re looking to avoi This content was created in partnership and with the help of Artificial Intelligence AI.