Snake River
Flows at Jackson Lake Dam are currently in the 2,000 cfs range. Water temps on the Snake are once again peaking over 68 degrees on most reaches except for those below the Hoback River and Fall Creek confluences. Be prepared by keeping your fish wet and releasing them quickly. There are a smattering of caddis in the early morning hours and PMDs starting around 11:30 am. Grasshoppers and carpenter ants are around on the upper reaches during the afternoon and craneflies will be around in the early morning hours and into early afternoon. There is still no consistency in terms of the sweet spot during the day when fishing is most productive – sometimes it is from dawn until 1pm, other times it is from 11am until 4pm, and still other days it is decent throughout the day. What we can say is that riffles and eddies are producing best in the afternoon and seams and troughs are performing best in the morning. If fishing banks focus both tight (within a foot and a half) and several feet off, as there has been a lot of variability in where fish are holding.
Streamers are producing in good fashion but there is a lot of variability in terms of time of day. An argument can be made that consistent action is leaning towards the early and mid-afternoon hours. Banks, riffle pools, the tail of seams, and troughs are fishing best. Go with small-ish to moderately sized imitations and fish them on floating lines or sinking tips in the INT to 3ips. Moderate speed retrieves with an even cadence is working best. Vary up your presentation if action slows.
Warm temps are creating algae growth on the lower reaches, some of which is suspended in the water column. Keep an eye on your rigging and be prepared to strip vegetation from your flies every now and then.
South Fork
Flows from Palisades Reservoir currently stands at approximiately 12,000 cfs. Visibility remains strong on the South Fork. Caddis are bouncing around in the early morning hours with PMDs still emerging in decent numbers from around 11am until 3:30pm. Terrestrials around in decent numbers are 1pm, making small to moderately sized attractor and terrestrial patterns worth using in the afternoon. Riffles, flats, and side channels have been amongst the most active waters to target. However, the fishing is starting to get fairly technical, so stay focused and rely on lighter leader/tippet and smaller and more imitative mayfly adult and emerger imitations. Other waters worth targeting with tandem dry and dry-dropper rigs include seams, eddies, and banks with slow to moderate currents.
Streamers have been producing well on all reaches, although you need to be more focused on your retrieve and presentation now more so than a couple o’ three weeks ago. Key waters to target include parallel drop-offs, banks and structure, riffle pools, and the slow current edges of seams. Go primarily with moderately sized baitfish imitations. Retrieves should be varied up with long hesitations in line strips from time to time. If using a floating line, consider dumping slack from reserve line after several retrieves in water with fast currents or deeper pools.
Flat Creek
We are two weeks into fishing Flat Creek since the opener on August 1st and there is decent action on all accessible pieces of the stream in the National Elk Refuge. Water temps remain cool, with surface highs peaking at around 62 degrees most days. Tricos and infrequen PMDs are emerging between 10 am and 11 am and continue until 3pm. Evening emergences can start around 7 pm. Evening fishing has been good in riffles and seams primarily. Daytime fishing is good in the same water and along eddy current margins and banks. Consider fishing grasshopper and beetle patterns during the morning hours. As usual, cranefly larva patterns are working well in eddies, along submerged structure, and undercut banks. Cranefly adult patterns can also draw eats and hookups if fished properly.
Salt River
The Salt is pretty low with flows at McCoy Bridge at just over 400 cfs and has been getting warm enough that WGFD ceased their electrofishing survey in order to reduce potentiall lethal stress for trout and whitefish. Nonetheless, temps have moderated with highs peaking between 65 and 66 degrees. Fishing is good on the low-gradient reaches in the morning, before getting tougher after 1 pm. Action on higher gradient sections can be good throughout the day. As on Flat Creek, tricos and infrequen PMDs begin to show up as early as 10 am (particularly the latter) and wane noticeably after 2:30 pm. Grasshoppers and carpenter ants are making an appearance, allowing fly fishers to match these bugs with smallish attractors, hopper patterns, and ant patterns. Fishing has been most productive in eddies, seams, and troughs. Deep undercut banks with slow to moderate currents also offer some opportunities. All of this can produce with nymphs fished on a short dropper rig – 14” to 24”.