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Top 10 for 2023

 Thanks to your support, here are a few things we were able to accomplish in 2023.

1. Ranch Water Temperature Project

Anglers helped select 17 locations in the Harriman State Park reach to monitor water temperature last summer. Some of the initial findings include:

  • Lower reservoir outflow = lower reservoir draft = lower outflow temperatures = lower temperatures at Last Chance

  • Lower outflow = greater cooling effect of groundwater = lower temperatures from Millionaires down to Pinehaven and beyond

  • In the rare cases that outflow is low during the middle of the summer when weather is hot, the highest afternoon high water temperatures—but also the lowest nighttime lows--occur at Bonefish Flats, where atmospheric effects have the greatest influence

  • Fish can easily move upstream or down out of that reach if they want to access cooler water during the day. This situation is rare because usually streamflow is highest in the middle of the summer due to irrigation demand.

2. DIRTT Plan for the Island Park to Pinehaven Reach

"DIRTT" stands for Developing Infrastructure to Reduce Temperature and Turbidity. A few goals of this program are to reduce fishing-season sediment export from the reservoir into the river downstream, reduce water temperatures, and address other water-quality issues in a changing climate.

Follow our monthly newsletters, blogs, or social media posts throughout the year as we share more.


3. 9 Years of Insect Monitoring

Did you know the Henry’s Fork Foundation has an aquatic insect monitoring program, now in its 9th year? The 2024 sampling, scheduled for March 18, will be the 10th installment in this statistically rigorous program. Insect decline has been a hot topic across the country, but what about on the Henry’s Fork? So far, data indicates insect abundance is driven by river conditions inherited from previous years, and more frequent drought could be playing a role. There is still much we can do to ensure the Henry’s Fork remains the envy of most trout streams.

View insect (macroinvertebrate) data here:

In spring, view Hatch timing data here:


4. Helping the Fish Population


This year, HFF’s Precision Water Management and Farms and Fish programs saved 27,000 acre-feet of water in Island Park Reservoir, contributing 115 cfs to winter flows and increasing the population of adult trout in the Box Canyon reach by around 575 fish two years from now.


5. Major New Findings in Island Park Reservoir Sediment

Research is indicating that sediment is not just building up from inflows to the reservoir, as with some “aging” reservoirs. Rather than more sediment coming in, more is being moved from the shallow west end during cold-front weather events. Did you know that the west end sits in a valley made of sediment, eroded off of the Centennial Mountains over geologic time? And HFF’s work reduced sediment exiting the reservoir into the river downstream by 150 tons this year?

6. River Clean Up and Fish Salvage

In 2023, staff and volunteers conducted four river cleanups along access sites and cleared out canned corn from the Big Springs area. Staff from the Henry’s Fork Foundation and Trout Hunter joined forces in the fall for a fish salvage near Chester Dam, moving fish from the Crosscut Canal, into the mainstem Henry’s Fork. Thank you to everyone who volunteered their time for crucial efforts to protect the river and fishery! If you’re interested in volunteering, please visit

7. Increasing Education Programs in the Community

HFF’s education programs have been expanding with the goal of helping community members of all ages connected to the watershed. In 2023, staff visited local classrooms, gave presentations, hosted field trips at HFF’s Community Campus, and planned activities like river cleanups, fish salvages, Youth on the Fly and HFF’s first Watershed Festival. Follow us on social media to stay in the loop on all of the Foundation’s education programs!

8. Landmark Research Comes Out of HFF’s Science Program

New research by HFF scientists and interns, and led by Water Resources Consultant Dr. Christina Morrisett, is getting noticed in the science and academic worlds. The research demonstrates how adopting center-pivot sprinkler irrigation over the last 40 years reduced diversion of streamflow for irrigation from the Henry’s Fork—but also reduced flow of groundwater back into the river. Groundwater inputs to streams are important for trout habitat, especially during summer low-flow periods.

9.  Drink Beer, Benefit Conservation

Have you seen the Henry’s Fork Hazy IPA in local stores? A huge thank you to Sticker Mountain and Grand Teton Brewing Company because a portion of the sales from the Henry's Fork Hazy IPA was donated to the Henry's Fork Foundation to support our work!

10. Henry's Fork Foundation in the News

The work at the Foundation has “made the news” in a couple of areas this year. Here are a few examples.

The collaborative Farms & Fish Program was featured by the US Department of Agriculture.

HFF’s Aquatic Ecology Program Manager, Dr. Jack McLaren saw his PhD research on Island Park Reservoir and fish habitat published in the peer-reviewed North American Journal of Fisheries Management.

Water Resources Consultant, Dr. Christina Morrisett was interviewed for BYU-Idaho Radio on her PhD research into irrigation practices and groundwater returns.

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