Almost all of our small steams are rounding into good fly fishing shape. The Teton River is one that is approaching such conditions, so it is worth looking at it a bit because it will become very popular quickly. The river in Teton Valley is its most popular stretch where wading and boating will increase very soon. So will recreational boating, so on stream diplomacy will be required as well as making early AMs and evenings best times for tranquil fishing . Several launch facilities are present and will have much use when recreational boating begins. Early season aquatic insect hatches include sallies, PMDs and caddis. Not to be totally overlooked, large stone flies blown in from the canyon reach below means long drifted patterns of each can be effective. When hatches begin in earnest drifting, then lifting soft hackled patterns also become effective.
Mountain Ash Creek; the least visited of Fall River Basin Streams
Fall River Basin in the southwest corner of the park currently offers the best fly fishing in our area. In saying that, we are looking at the big picture where tranquility, great scenery, and superb fishing reign supreme. The major streams here include Bechler and Fall Rivers and Boundary, Mountain Ash and Proposition Creeks. The still waters are Beula and Hering Lakes. For this report, let’s look at the streams. We will look at the lakes in the next report.
Each of these streams is not influenced significantly by man-made development, except for a minor inflow from Grassy Lake Reservoir to Fall River. Currently each is at natural flow; clear, cool and hosting a great population of cutthroat and cutt-bow hybrid trout. No whitefish or suckers are present! Float fishing is prohibited: wading only! There are no introduced brookies in Bechler River and Boundary Creeks where the other streams host them.
Currently top water is approaching its best (until terrestrial insects form in huge populations). The hatches going on now include diminishing sallies, numerous PMDs, caddis, and an excellent evening brown drake hatch. In good water years, like this year, there is a good green drake hatch that begins each day in mid-July during afternoons when water temperatures get into the low 50s in Deg. F. Six weight rods, floating lines and long leaders are best. So is stealth, so minimize bank side appearances.
If there are any disadvantages to visiting these streams. it is at least the three mile walk through bear country and the need for DEET to ward off insect pests. For the Bechler River-Boundary Creek side Bechler Ranger Station is the jump-off point. The station is fully staffed 24/7, sells park licenses, has horse party facilities, and solid information about trail conditions. For the Fall River side, access is from the Ashton-Flagg Road. Primitive, but passable roads give closer access to the other streams. We, at the shop can identify these for you and we can provide further information for all waters.
We will keep up and report on fishing conditions in Fall River Basin throughout the season simple because it is such a special place in this area.
Flow has been up & down slightly and around 13200 cfs at Irwin (13900 cfs at Heise, about 6000 cfs at Lorenzo), and Palisades Reservoir is essentially full.The giant stone fly hatch is in the canyon, and is being attended by boating anglers. So boat launch facilities from Conant Valley to Byington are getting use. Above, the river remains a bit cool, so top water fishing is yet to peak. Try rubber legs, annelid and stone fly nymph patterns and fly rod jigs. There is certainly less boat traffic from the dam down to the Spring Creek site than on the river below.
Water quality and insect hatch Information from Dr. Rob Van Kirk’s Monday drainage water status report
Water quality us holding up well and is better than average for this time of year. Mean daily water temperatures have stayed at or below average and below last year’s values at all stations except Parker. Daily high water temperatures have exceeded 70 degrees over the past few days at Buffalo River, Pinehaven, St. Anthony, and Parker. Peak water temperatures are happening between 3:30 p.m. and 8:30 p.m. now. Dissolved oxygen concentrations are good at all locations.
Turbidity at Pinehaven increased briefly to 4.0 NTU on Friday as expected but has since dropped to less than 3.0 NTU, where it was prior to Friday’s outflow increase. For comparison, average turbidity values for the date are 6.1 NTU at the dam gates and 4.5 NTU at Pinehaven, Last year’s daily values on July 10 were 9.4 NTU and 7.9 NTU, respectively.
Timing of aquatic insect hatches has not changed much with respect to the 2014–2022 average over the past two weeks, as water temperatures have stayed close to or slightly below average. Hatch timing in the river reach between Island Park Dam and Pinehaven is 5–6 days later than average but at or a few days ahead of that in 2022.
Flow out of Island Park Dam was raised to about 1300 cfs yesterday, and since July 4th its progress graph looks like a step function as irrigation water demands kick in.The most significant insect happening is the building evening brown drake activity on the river below the US Highway 20 Bridge aside from AM spinner falls throughout the upper river. Especially from in Box Canyon down to Last Chance you will see the peak of recreational activity. Be patient and show the floating public that fly fishers are a “polite bunch.” ‘. The best way to escape the bulk of the plastic/rubber flotilla is during AM spinner falls and evening brown drake activity.
Flow out of Mackay dam is still close to 1000 cfs. That to high for safe wading. It’s an unusual situation because of run-off coming into the reservoir from above. Water is flowing even down to Arco wher years ago good fishing was possible. This high flow will end soon, and we will report such because this stream and its Copper Basin headwaters are important destinations for many fly fishers.
Other than the big stone fly event ( Bugs are now into the lower canyon), we had a serious incident on the river yesterday. Three anglers in a drift boat got too close to the big feeder gates and came nearly getting sucked through. They were luckily relieved of the situation by efforts from hard working first responders.
A long boating season is coming up on this big, powerful river, and the potential for unhappy incidents like this one, and worse, are bound to happen. We and all other businesses that serve boating, and wading fly fishers ask that we do as much as possible to remain safe. It is not because you are customers, it is because you have families and/or are part of the community to which and you contribute to in many ways. So please resolve in the hours before you arrive on the river that you will strive to be safe.
This conversation is going to be general. But because so many area cutthroat spawning streams opened to fishing a few days ago there is a particular reason for fishing these, and that is because of hosted beaver ponds. Beaver ponds provide so many advantages for trout. They offer relative overhead cover, cool water this time of the season, a rich variety of food forms from damsel flies and speckled duns on down to leeches (easy protein), scuds, and even mice and snakes. You will find these pond only on low gradient sections of small streams (no way could beavers dam the South Fork!), but some can be large enough to host a flotation device (See above photo). Now is the time for best fishing on these because as summer advances they warm like all other waters.
So where does one find these ponds? Many of the best are off the beaten track. The Willow Creek drainage is a good place to start looking. Such as Cranes Creek, Hell Creek, Gray’s Lake Outlet, lower Homer Creek, Tex Creek are good candidates. All Palisades Reservoir tribs host beaver ponds and so do Salt River tribs coming out of Idaho (Crow, Jackknife, Stump, Tincup). Palisades Creek, just above the lower lake, hosts some, and so do several Henry’s Fork drainage streams. The same applies to Teton River and Big Lost River tribs. Use Google Earth and look for their presence.
Fish in these, usually brown, brook and cutthroat trout can attain surprisingly large sizes. Browns up to ten pounds use to inhabit Cranes and Willow Creek and Gray’s Lake Outlet beaver ponds. Cutthroat in Centennial Valley streams range exceed twenty inches in length. Brook trout exceeding twenty inches still inhabit Duck Creek beaver ponds.
Other streams are now worth a visit. Bitch, McCoy, Palisades and Robinson Creeks are near run-off free. Golden stones, PMDs, sallys and PM caddis are active on these. Warm River below it spring offers Brook, brown and rainbow trout (relative solitude compared to nearby Henry’s Fork) responding to the same aquatic insects. b
Fishing in the upper section of the Harriman State Park section will soon take a somewhat back seat during PMs to the lower section. March browns are mostly gone, Green Drake activity is tumbling, PMDs are getting smaller in size, but flavs remain for good PM fishing and AM spinner falls. But for brown drakes, the peak hatch peak is soon to come, and the best of their hatch will be accessed via Wood Road 16 (WR 16). For sure there will be some brown drakes throughout the entire Harriman reach (same with flavs), but there is one big reason why the best concentration is on the lower section. See the above photo? It was taken of a river section about a half mile above the WR 16 access.The US Highway bridge is at upper right. What is significant here is that water flowing from Last Chance on down to and past the bridge is warming because of water in Island Park Reservoir and inlets from Silver and other Park lakes are warming (all are shallow), and so is weather, helping to diminish dissolved oxygen in the river. However inflow from Big Osborn Spring adds a large amount of cool water to the river making better conditions for the brown drake population in the river below. Brown drakes emerge best during evenings but they are sure to peak soon. Fish are in the river “Twenty-Four Seven” and they will be gorged on these active insects just before their emergence peak. So consider being on this part of the river very soon. .
Water Quality Section from Dr. Rob Van Kirk’s Henry’s Fork Drainage report filed July 3rd.
Overall, water quality continues to be excellent throughout the watershed, with the exception that afternoon high temperatures are starting to exceed optimal at some locations. Mean water temperatures yesterday were very close to average throughout the watershed, but afternoon highs exceeded 70 degrees at Buffalo River, Pinehaven, St. Anthony, and Parker. Dissolved oxygen concentrations are good in all river reaches.
Timing of aquatic insect hatches has not changed much with respect to the 2014–2022 average over the past week except at Marysville, where it has moved from 9 days later than average to 8 days later. Hatch timing in the river reach between Island Park Dam and Pinehaven is 5–6 days later than average but at or a few days ahead of that in 2022. Hatch timing at Flat Rock, Ashton Dam, and St. Anthony is still 1–4 days behind average but 1–3 days ahead of last year.
About 1000 cfs of water is coming out of Mackay Dam. This means difficult and somewhat dangerous wading in the river below. Look for flow out of the dam to remain this high until run-off from the upper drainage begins to drop.
The Firehole River still offers good fishing, even though water there is warming. ShoshoneLlake still offers the best still water fishing if you follow the strategy offered in our last fishing report.
Fall River streams are rounding into shape, but water is high. Best current strategy is to fish patterns that simulate drifting earthworms (annelids) until waters drop. All meadow sections are wet and mosquitos within the timbered areas are NUMEROUS and fierce! Bring DEET to survive walks through these areas. The Ashton-Flagg Road, rough in places, is open to Grassy Lake Reservoir. It is closed just beyond at the Bridger-Teton USFS boundary
