Some of our small streams are beginning to shape up. Beaver, Birch, and Medicine Lodge creeks are all in good shape with flows about normal for this time of year. Both Big and Little Lost Rivers drain higher country, and therefore are still running higher than normal. The Big Lost still runs water past Arco and onto the INL. McCoy and Bear Creek are high and a bit discolored, but offer some fishing if you do not mind presenting anything that looks like a drifting earthworm. Cutts are in both creeks either having spawned or are about to, and the sizes they range to will surprise you. I avoid areas where they are spawning, but concentrate on presenting flies on slower and deeper waters. Both Buffalo and Warm River are in good shape with PMDs and caddis being active in good numbers. Forget about fly-fishing the Blackfoot River below the reservoir until the first of October. The river above the reservoir opens to barbless hook, C&R (for cutthroat) fly fishing on July 1st.
Some roads to small waters remain closed. For example the Ashton Flagg Road is closed beyond the South Boone Creek crossing, and the Snow Creek Road has yet to open. The Cave Falls Road is open, but soft in places. Warm River is one of the better small streams to try. The lower river will be crowded because of the nearby campground and easy access. Fewer anglers will be near the Warm River Spring or near Pole Bridge campground because the giant stonefly hatch on the nearby Henry’s Fork is in full swing. Try wet attractor, small bead head nymph,and caddis life cycle patterns. Tributaries to Palisades Reservoir are sure to be high for a while. Of the Salt River tributaries, Jackknife Creek might be in the best shape where small woolly bugger types and bead head nymphs would be best bets for action. All streams draining high country will host run-off for a while.
Many back country roads are opening up meaning that some of our quality small waters are now approachable. However those that drain high country remain high and discolored. The Blackfoot River provides a good example of this situation. The river above the reservoir is running very high, but opens to fishing on July 1st. Roads leading to the river below the reservoir are open, but the river, now open to fishing, is running very high. The same applies to Fall and Teton rivers: approachable but running high and discolored. Expect the same for Palisades Reservoir tributaries, Salt River tributaries, Little Lost River drainage, Medicine Lodge Creek, and Robinson Creek. Warm River above Robinson Creek is running high and clear. Birch Creek is the exception. It is in good fishing shape. Being mostly of spring creek origin, it will remain so through the season.
Flow in the Blackfoot River above the reservoir is much higher (710 cfs at the Henry gage with 110 cfs being normal) than it has been for years. This is great news because silt accumulation compromises parts of this river. A flush from these flows can benefit both trout and aquatic insects. With more than normal snow pack remaining in the drainage, high flows could be around for a while making the outlook for cooler flows through the summer very good. What could really be beneficial here would be to have a number of consecutive years with flow this high in the river.
It’s a different year than the last few because of our winter with abundant snowfall in the high country. Not only is access difficult or impossible because of road conditions, and with warmer weather coming on, most streams are high and with discolor. For example, last year at this time the lower Blackfoot River was worth fishing with flow around 100 cfs at the Shelley gage. This year with roads mostly blocked and nearly 500 cfs at the same gage, it is time to go somewhere else.
Our 9-24-16 small streams fishing report offered some thoughts about the effects of significant rainfall on stream flow. We currently have a repeat of the weather conditions prevailing around 9-24. So again looking at USGS flow gauges on streams not influenced by an upstream reservoir reveals flow increases because of current storms. Current weather has been just what is needed to optimize seasonal aquatic insect activity for certain species, but it also adds food forms because of temporarily increased bank and bottom erosion. So it seems a good idea to once again include patterns imitating these food forms as well as streamer, caddisfly and mayfly life cycle, and terrestrial insect patterns in that fly box.
Flow out of Blackfoot River Reservoir has been reduced to 67 cfs. Not good for resident trout in the river below. Some good fishing on the Teton River in the Basin remains with BWO, mahogany dun and terrestrial insect activities bringing action on the river here. More good news here is that daytime recreational boaters are diminishing as cooler weather proceeds.
Observing USGS flow gauges reveals much information, even for streams not hosting such items. The big rain we had the last few days increased flows significantly according to readings on these gauges. So it is likely that a temporary flush happened on all these streams including those upstream of a reservoir (most of which are just beginning or soon to be impounding water). The increases are enough to bring about a temporary change in fly-fishing strategy by causing enough bank erosion that such as worms and immature burrowing insects are temporarily abundant food forms. So for the next few days, be sure to have such as San Juan worms, Suede Juan worms, and wooly buggers in that fly box.
Flow out of Blackfoot River Dam was reduced yesterday resulting a drop at the Shelley gage from 128 cfs to 87 cfs. This flow is not good for hosting fish and means they will face a tough time this winter. Let’s hope for their sake there are no further flow reductions.
Look for terrestrial insect patterns to be important flies for action on most any small stream until a killing frost comes along. Another consideration is that with shortening days and cooler weather, and absence of AM trico activity, afternoons will be the best time to find action. Also consider that with the uncertainties of a good snowfall this coming winter any tail water fishery (portions of Big Lost, Blackfoot, and Portneuf Rivers) will have low flows for the remainder of the season because of actions to fill depleted reservoirs.