
Snake River
Flows from Jackson Lake Dam stand at approximately 2,250 cfs. Primary hatches on all reaches include PMDs and Claassenia stoneflies. Despite continues warm and dry weather, we are starting to see Hecuba begin to appear – a sure sign of autumn approaching along with Claassenia – especially on the higher gradient reaches from Deadman’s Bar down to South Park Bridge. Riffles and side channels are prime water to target at the moment, with the former kicking into gear in the afternoon. Seams, confluences and eddies are worth targeting as well. Banks can good, but be sure to spread your cast out – targeting both within a foot and being well outside by up to six feet if currents are slow or moderate. Suspended vegetation in the water column has been frequent on the lower reaches below South Park, so keep an eye on your flies and check them to see if you are hooking into algae frequently.
Streamers have been producing in good fashion with the best action occurring on the middle reaches from Moose Bridge down to Pritchard Creek. Expect action from all sizes of fish with downstream presentations outperforming upstream retrieves. Moderately sized straight shank and jig hooks are working equally well. Target banks, structure, and troughs primarily. Riffle pools, confluences, and seams are worth hitting as well. Go with floating lines or short sinking tips in the INT to 3ips range and moderate to fast retrieves. No big difference at the moment between faster and slower currents.
South Fork
Flows from Palisades Reservoir stand at approximately 10,750 cfs. PMDs have waned some but are still out in the afternoon in decent numbers, meaning riffles, seams, troughs, flats and side channels should be your focus at that time of day. Mutant stones are starting to appear in decent numbers as well. This gives fly fishers good opportunities throughout the day with large to moderately sized attractor patterns. Early morning dawn patrol – 7am as a start time – can really be a good approach when going this route, as they have been very active in the morning hours (no surprise there). Target banks, structure, troughs, and the inside current margins of riffles. As on the Snake, suspended vegetation is starting to creep in, so check your flies often for algae residue and trailing material.
There is decent to good streamer fishing on all reaches with the canyon sections from Conant down to Byington fishing best by a smidge. Slower water and slow retrieves is the name of the game with slow retrieves in faster current producing in inconsistent fashion. Moderately size patterns are producing best, although larger patterns are working equally well below Twin Bridges. Focus primarily on sinking tips in the INT to 6ips range and target banks, structure, the slow current margins of seams, riffle pools, and side channels.
Flat Creek
Undercut banks and deep lies next to structure has been the prime holding lately. Fish are feeling the pressure and spooking easily, so consider going down to 6X with your leader and tippet. Cranefly larva patterns are not producing as well as they have been over the past couple of weeks. Instead, midge, trico, and small mayfly nymph imitations have been working best. Trico emergences in the morning have been short – one to one and a half hours – but very much worth targeting with trico adult patterns (riffles, seams, and eddies have been working best).