The lower river is discolored from construction activities at both Ashton and Chester dams. To keep up on these activities go to the Henry’s Fork Foundation (www.henrysfork.org) home page and look at the “Latest News” box for updates.
The last few feet of draw down of water from Ashton Reservoir should be completed this week. Turbidity in the river below the dam continues because of by-pass tunnel construction which will continue through the week. The river is cutting a new channel in the upper end of the reservoir adding fines to the river below. After draw down and tunnel construction are completed, look for improved water quality in the river below. The Henry’s Fork Foundation (www.henrysfork .org) publishes progress and observation reports on the Ashton Dam construction regularly.
Because of construction activities on Ashton Dam the river below clouds up from time to time. So fishing below the dam has slowed. On the upper river Last Chance-Harriman is fishing well. Morning spinner falls, Mid-day and early evening terrestrial activity and evening caddis activity make for action. Want a chance at a big cutthroat or brookie in the Henry’s Fork? The flow out of Henry’s Lake is being dropped. So fish that have come out of the lake and have survived the summer in the reach known as “Henry’s Lake Outlet”, mostly cutthroat but some hybrids and brookies, will be moving downstream into the Tubs above Macks Inn and eventually down to Island Park Reservoir. Best way to encounter these is presenting streamer patterns from the Tubs on down through Coffee Pot.
We are all greatly interested in effects of Ashton Dam construction on the river below. It appears that water will continue to be released until late next week in order to get the reservoir water level down 17 feet for work to be performed. Therefore look for silt to be released through this time frame and impact river clarity at least as far downstream as the Chester Dam backwaters. So far it appears that released silt is within expected amounts. The Henry’s Fork Foundation (www.henrysfork.org) posts pictures of the river and is monitoring the impacts on it.
On the upper river around Last Chance and the Harriman reach, PMD spinner falls are bringing AM action, and terrestrial insect patterns bring action during daytime hours. Have you ever twitched a hair mouse around grassy banks here around twilight?