Snake River
Low flows and gin clear water on every reach of the Snake at the moment. BWOs and chironomids are the primary bugs on the water, with the former occurring primarily on cooler, wetter days. Look for them to be out in a short window from around 2pm until 5pm. Chironomids can be out as early as 10:30am. The best surface action has been at the head of riffles, ledge rock pools, eddies, and side channels. Nymphs are producing in the same water with chironomid, mayfly, and cdc soft hackle patterns working well. Whitefish are spawning in earnest, so roe patterns are very much worth fishing in riffles (particularly the head of riffles). It can be very much worthwhile to focus on the lower half of the water column before 11am, the upper half between 11am and 1pm, and the upper 1/3rd of the water column after 1pm.
Streamers aren’t getting into much before 11am but kick into gear after and produce best after 12:30pm. Most of the action is occurring in eddies, seams, riffle pools, and along banks and submerged structure. Moderately sized patterns are working best. Fish these of floating lines or sinking tips in the INT to 3ips range. No big differences between longer 12’ tips and shorter ones in the 7’ range, but definitely vary up your retrieves with a focus on slow to moderate tempos.
South Fork
As on the Snake, the South Fork is experiencing low flows and crystal clear water, with every reach fishing is similar fashion. BWOs are the most prominent hatch (other than chironomids) with the most prolific emergences occurring on cooler, cloudier, wetter days from around 1pm to between 4pm and 5pm. October caddis are waning big time, but you might be able to see a couple on a given day. Riffles, troughs, seams, and side channels are key waters to focus on.
Nymphs are working as well as dries and in the same water and outperforming them in eddies. Chironomids are your best choice, followed by BWO imitations and then everything else. The one caveat here is that, with whitefish in full spawn mode at the moment, roe patterns can produce better than anything else, especially in riffles.
Streamers continue to perform well on all reaches with the upper reach in Swan Valley and the lower reaches below Twin Bridges taking the edge slightly. Small patterns are working better than moderately sized and larger baitfish imitations. The best holding water to target include troughs, banks and structure with moderate depths and slow to moderate currents, seams and eddies. Floating lines work fine, but if using a lightly weighted patterns, go with short sinking tips in the INT to 3ips range.
