Henry’s Fork, September 12th, 2023

No killing frosts on the upper river to date. That means terrestrial insects remain numerous but spinner falls are diminishing. For the river below, same situation (excepting for BWOs), but brown trout are beginning to move, so streamers are in order during low light conditions. Some other good news is that recreational boating on the river is fading away on the river.

Headlines from Dr. Rob Van Kirks Henry’s Fork Drainage Water Status Report Filed September 11th.

• Last week was average in temperature and wetter than average; water-year total precipitation is 111% of average with only 20 days remaining in the water year.
• Diversion and lower-watershed stream flow targets continue to be met with no reservoir draft.
• At an average outflow of 468 cfs, Island Park Reservoir has gained 159 ac-ft/day over the past five days and is 63.5% full, compared with 46.1% on average.
• Water quality is excellent throughout the watershed in all measures.

Rob Van Kirk, Ph.D.

Senior Scientist

Henry’s Fork Foundation

P.O. Box 550

Ashton, ID 83420

208-881-3407 CELL

208-652-3568 FAX

[email protected]