General Conditions
Summer heat is finally tapering off, and cool fall weather is bringing prime fishing conditions across the region. From here on out, expect fishing to steadily improve as water temperatures continue to drop. Early mornings and evenings remain the most productive times for targeting trout, with receding flows helping to concentrate fish in riffles and tail-outs. Whether you’re dusting off your gear or picking up a new rod, reel, or fly line for the season, now is an excellent time to get out and enjoy fall fishing in Idaho. Don’t forget to check the flows before you go!
Boise River – In Town
The Boise River in town is flowing just above 600 CFS, making it an excellent wading option this time of year. Float season has wrapped up, so now is the time to carefully work your favorite riffles and tail-outs for actively feeding trout. Nymphing is the most consistent approach, and don’t hesitate to use split shot to keep flies near the bottom. Streamers are also a solid option for anglers looking to cover more water.
Fly Selection: #14-20 FB Pheasant Tail, #14-18 Hares Ear, #16-20 Copper Johns, #16-18 Duracell, #16-18 Blowtorch, #18-22 Zebra Midges, #18-20 Olive Micro Perdigons, Sculpzilla #4, #6 Mico Dungeon (Olive, White, Natural)
Owyhee River
Flows remain just over 200 CFS, keeping fish relatively spread out for this time of year, though we can expect levels to continue dropping as fall progresses. Hatches are light, dominated by midges, with Blue Winged Olives producing fish throughout the day. Look for caddis activity in the late afternoon and evening. Nymphing remains the most reliable method — try a extra small, or small Oros. A dry-dropper setup is a more natural presentation to consider for even spookier fish. Streamer fishing has also been productive with small, jigged streamers retrieved slowly.
As October approaches, brown trout will begin spawning. Please take care to avoid wading through shallow riffles where redds are visible to protect future fish populations.
Fly Selection: #20-22 Zebra Midge, #20-22 Demon Midge, #20-22 Splitcase BWO, #14-16 Galloup’s UV Caddis Pupa, #20-22 Hackle Stacker BWO, #16-18 Corn Fed Caddis, #18 Para Ant (Black/Red).
South Fork Boise River
Flows have dropped below 300 CFS, opening up great wading opportunities. October Caddis are officially on the menu, making fall evenings a special time to target rising trout. Afternoons and evenings are currently most productive, with sporadic BWO and midge hatches throughout the day. Between hatches, nymphing is effective, and dry-dropper rigs work well for wary fish in shallow water.
The river fishes best with 4X tippet for most nymphs, 5X for small dries, and 6X if you’re presenting size 20–22 patterns.
Fly Selection: #14-16 Blowtorch, #16-18 Spanish Bullet, #6-8 Restless Stone, #14 Rosa Red Tag, #12-14 Frenchie, #8-10 Elk Hair Caddis (Orange), #8-10 Burkus October Caddis, #14-16 Corn Fed Caddis, #18-20 Last Chance Cripple BWO
Silver Creek
Silver Creek is settling into its classic fall rhythm, with crisp mornings creating solid fishing conditions. Stealthy wading and delicate presentations are essential for success. Morning Trico hatches are tapering off but can still produce surface action on calm days. Baetis are still important to have, especially under cloud cover, while Mahogany Duns are now making a welcome appearance and offering some incredible dry fly opportunities. Don't be shy to throw streamers under cloudy or low light conditions.
Fly Selection: #20-22 Sparkle Dun Baetis, #20-22 Brook's Sprout Baetis, #16-20 CDC Biot Dun Mahogany, #18-20 Biot Comparadun Mahogany, #16 King Splitsville Spinner, #14-16 Spent Ant (Black), #20-22 Hackle Stacker Trico
Snake River
The Snake continues to provide exciting opportunities for both bass and carp in western Idaho. Streamers, poppers, leeches, and crawfish patterns are key. Target shaded water during the heat of the day and focus on rock gardens or overhanging structure. For carp, stalk the shallow flats and present leeches or small nymphs carefully — these fish are challenging but rewarding.
Fly Selection: #10-12 Balanced Leeches (Black or Brown), #10 Beadbelly Leech (Olive), #8-10 Wooly Bugger, #8 Zonker Minnow (Yellow, Olive, White), #8 Sculpzilla (Olive, White, Natural), #4 Assorted Bass Poppers, #4 PJ Skater Popper, Galloup’s Sex Dungeon (Olive, Yellow, White)
Stillwater
Lake fishing is beginning its seasonal transition back into prime conditions. Warm summer water, algae blooms, and deep-holding trout have made many lakes tough recently, but things will improve as temperatures cool. It is a good idea to keep a thermometer in your pack so that you can check surface temperatures.
Alpine lakes remain a great late-summer option for trout and offer a refreshing escape into Idaho’s backcountry. Bring a mix of Woolly Buggers, hoppers, Parachute Adams, Purple Haze, chironomids, and balanced leeches. Grab your favorite day pack and take advantage of the last part of our alpine lake season!
Duck Valley and other regional stillwaters will soon fire up for early fall. Stock up on leeches and chironomids, and keep an eye out for our expanded chironomid selection arriving soon at Idaho Angler. Duck Valley permits can be purchased online here.
Steelhead
Steelhead season has arrived in some areas and is fast approaching in others, with encouraging passage numbers for the fall and winter run. Stop by Idaho Angler to check out our new lineup of Dave Tucker’s expertly tied steelhead flies, and get set up with the right spey rods, reels, and lines to chase the “fish of 1,000 casts.”
