Bighorn River Fishing Report: Nymphs, Streamers, and Midges in the Winter Wonderland

This is Artificial Lure checking in with your Bighorn River fishing report out of Fort Smith and the Big Horn, Montana country. No tides to worry about here in the high plains, just river flow and weather. The Bighorn is running low and clear for December, classic winter conditions. According to the USGS gauge at St. Xavier, flows are holding steady in that 3,000 cfs neighborhood with good clarity most of the day. Mornings are cold, with air temps starting in the teens and working into the 30s under a mix of clouds and sun as reported by the National Weather Service. Expect a light north breeze, but we can still get some windows of calm. Sunrise is right around 8 a.m., sunset about 4:30 p.m., so you’ve got a tight mid‑day bite window. Fish activity is very much in winter mode. Montana Outdoor’s Bighorn River Fishing Report from Angela Montana on December 9 says the trout are still “fighting back” but you’ve got to slow everything down. Browns are mostly post‑spawn and sliding back into deeper winter water. Rainbows are podded up in softer seams, drop‑offs, and tailouts. Don’t expect crazy numbers, but the quality has been excellent: solid 16–20 inch bows with a few bigger browns pushing the mid‑20s landed this week by guides running nymph rigs in the Three Mile to Bighorn stretch. Best producers right now are nymphs and the tiny stuff. Montana Outdoor and Yellowstone Angler both note strong midge and baetis nymph action across our region. Think **Zebra Midges**, **$3 Dips**, **Perdigons**, and **Little Spankers** in sizes 16–20, fished deep under an indicator with a bit of split shot. Sowbugs are always Bighorn bread‑and‑butter—pink or grey, size 14–16. Fish them slow, almost dead‑drifted, and let those flies hang in the softer inside edges. For those who can’t leave the meat at home, streamers are still in play, but you’ve got to crawl them. Yellowstone Angler’s cold‑water report this week recommends patterns like **Home Invader**, **Sex Dungeon**, and **Silk Kitty** in olive, black, or white, swung or stripped painfully slow. On the Bighorn, scale that down a hair: small olives and sculpin patterns on a sink‑tip, fished along ledges and drop‑offs, have moved a few heavy browns early and late. If you’re a dry‑fly diehard, you’re hunting midges. On overcast, wind‑friendly days, look for heads in the softer slicks. Harrop‑style hanging midges and small midge clusters in sizes 18–22 will get it done. According to recent regional reports, the hatch is light but consistent once the mercury bumps above freezing for a few hours. Bait anglers working the Afterbay and slower side channels have picked up some nice rainbows on nightcrawlers and small marshmallow‑and‑worm combos drifted near the bottom. A few walleye have also been reported out of the lower river on jig‑and‑minnow rigs, though trout remain the main attraction. Couple of local hot spots for you: • **Afterbay to Three Mile** – Great wade options, consistent pods of rainbows on sowbugs This content was created in partnership and with the help of Artificial Intelligence AI.