Sun Valley Area
Fly Fishing Forecast
August 26 – September 2

The rivers continue to drop, cool, and clear. The trout are becoming more aggressive, feeding on revitalized late-season hatches. The foliage is beginning to turn from summer green to gold. The fall reset is coming.

Silver Creek

The cooler weather this weekend should help the Creek escape the summer doldrums. Of course, you may see a few Tricos, but the early-morning hatch activity will shift to the late morning and will consist mostly of Baetis. Callibaetis duns and spinners will be the main fare in the afternoon. Hoppers, ants, and beetles are all working, especially when the wind blows. Nymphing is productive as usual with small Baetis, midge, or Callibaetis nymphs. Reminder: As of Aug. 24th, the Kilpatrick Bridge and access to the Preserve from the east side will be closed for construction. Construction on the bridge, as well as dredging the Pond, is scheduled to run through January 4th. During this time, there will be several different closures in place—float tube access, recreational floating, waterfowl hunting, parking, and hiking. For questions about the bridge replacement, contact Blaine County at (208) 788-5500 or blainecountyid.gov. Direct questions about the dredging project to the Silver Creek Alliance at director@silvercreekalliance.org or (208 ) 720-4525. For questions about access to the Silver Creek Preserve, please contact (208) 788-7910.

The Big Wood

With the low water, we still need to be mindful of water temps, especially on the lower river. However, cooler temps are coming, which will make the trout happy. You can expect to find a few Tricos, Baetis, caddis, PMDs, as well as flying ants and hoppers depending on time of day and location. Small nymphs trailed behind a dry are productive, and streamers are also worth a try. Once things cool down, keep on the lookout for the last big mayfly of the year, the Hecuba (Red Quill).

Big Lost below Mackay

Flows are down a bit to around 340 CFS. These flows make the river more accessible for strong waders, and they should continue to drop as we head into September. There are plenty of feeding trout in the riffles, buckets, as well as along the shallow edges of runs. Tricos and Baetis are the main midmorning fare, and craneflies are always a good option. In the afternoon, the fishing slows down dramatically, but nymphing will still produce.

Upper Big Lost

The water is low and clear, so stealth and mobility are critical. It is much cooler in the mornings so no need to start early; give the trout and bugs a chance to warm up. To find fish, focus on the deeper, greenish runs and be prepared to cover a lot of ground. There are still Tricos and an assortment of small mayflies and caddis around. Hoppers and flying ants are a good choice as well.

Salmon River

There are floating and fishing mitigations in place to protect spawning salmon, so please check with the shop or the SNRA headquarters before you go. The flows are low and, while some don’t mind dragging their boats, the floating season is mostly done. Wade fishers will find plenty of pull-offs to park and search. For flies, try hopper, caddis, or Spruce moth patterns trialed by a beaded nymph.

South Fork of the Boise

Flows are holding at around 800 CFS. Typically around the first of September, flows drop to 600 and a couple of weeks later 300 CFS. The floating season is wrapping up. You can expect to find Pinks, Baetis, caddis, craneflies and the usual array of terrestrials.

Local Ponds

Lake Creek, Penny Lake, and Gaver’s Lagoon should be stocked between August 24-28. There is still time to get the family out for some summer fishing fun.

Recommended Flies

Silver Creek: Baetis 20-24 | Callibaetis 16,14 | Tricos | Damsels | Terrestrials | Zebra Midge in black, red, or olive | Small Pheasant Tails | Streamers

Big Lost: PMDs size 16 | Yellow Sallies | Crane Flies | Golden Stones | Baetis 18,20 | Midge 20-24 | Streamers

Big Wood: PMDs | Caddis | Red Quills | Chubby Chernobyl | Rubber Legged Stones | King Prince | Streamers

Salmon: Caddis | Spruce Moths | Hoppers | Chubby Chernobyl | Rubber Legged Stones | King Prince | Streamers

Southfork of the Boise: Pink Alberts | Baetis | Flavs | Midge | Rubber Legged Stones | King Prince | Streamers