Bighorn Montana Fishing Conditions Ideal for Trout on the Fly

Good morning from the banks of the Bighorn River, this is Artificial Lure with your Big Horn Montana fishing report for Monday, May 19, 2025. We are deep in prime spring fishing, and the river is showing off. Sunrise was at 5:39 am and sunset will be at 8:29 pm. No tidal changes to worry about in Montana—your bite windows today will follow water temperature and light. We’re expecting clear skies, a light breeze, and daytime highs in the upper 60s. Water flows remain steady and clear, running near 2280 cubic feet per second, with an afternoon water temperature hanging around 48 degrees. Short version: it’s about perfect out there today for both waders and those in a drift boat[4][5]. Fish activity is strong. The big story lately is healthy rainbows and browns in the 16 to 20 inch range being caught with regularity, and several folks have managed trout pushing the 22 inch mark[3][4]. Most of the action is happening subsurface. Nymphing is hands-down the most productive method right now. Top flies are Tailwater Sowbugs in size 14 to 16, Baetis and BWO nymphs, midge pupa and larva in size 18 to 22, and the old reliable scuds—try Two-Tone or Orange Scud for your “up fly.” Carpet Bugs, UV Yum Yums, and the Flashback Quill Nymph are also putting fish in the net[1][3][4]. If you are a streamer junkie, Sparkle Minnows, Geisha Girls, and Skiddish Smolts have been producing, especially with a slow retrieve in the deeper, slower water[2]. Don’t pass up a worm pattern either; red or pink San Juans have been grabbing some good ones. Not much surface action yet, but if you insist on a dry, look for risers later in the afternoon and go tiny with a #20 Sipper Midge or CDC Midge. As for bait, fly fishing reigns supreme here on the Bighorn. If you are after numbers and size, stick to tandem nymph rigs with a sowbug or scud up top and a tiny midge dropper fished deep and slow. Hot spots this week: The section just below Afterbay Dam is always a good bet, especially in the morning. For those willing to walk, the weed beds near Soap Creek are holding some bruisers—just beware if spring rains turn the water off-color down there. Reports from the last few days have been nothing short of stellar. Anglers are consistently finding trout throughout the system, and the river is in great shape. Stop by the local fly shops for the latest scoop and to stock up before heading out. That’s your report for today. Tight lines from Artificial Lure—here’s to your next big one on the Bighorn[3][4][5]. This content was created in partnership and with the help of Artificial Intelligence AI.