Water Quality
Fish of the Month: Year 11
As it is the afternoon of December 31, I am closing the year with my annual fish-of-the-month blog, this one at the end of my
Rob Van Kirk
December 31, 2025
Water Supply
Water Supply
Winter Flows on the Henry’s Fork: What Anglers Need to Know
The Henry’s Fork Drought Management Planning Committee (DMPC) met on Monday, November 24 to set this winter’s outflow and reservoir-fill strategy for Island Park Reservoir—an
Jamie Powell
November 26, 2025
Water Quality
The River Rundown: Your FAQs from June 2025
“It feels like July!” was a common sentiment shared around the watershed last month. Anglers enjoyed Brown Drakes on the Ranch three weeks earlier than
Christina Morrisett
July 8, 2025
Water Quality
Henry’s Fork Summer Fishing: Predictions for water supply and water quality in 2025
This time of year, one question is top of mind: what can we expect from the summer fishing season on the Henry’s Fork? Every spring
Rob Van Kirk
April 14, 2025
Water Quality
Behind the Scenes of HFF’s Daily Water Report
What is HFF’s Daily Water Report? After the severe drought of 2016, which resulted in what is still the poorest water quality we have recorded
Rob Van Kirk
March 7, 2025
Water Supply
Island Park Winter Flow in 2025: How did we do?
Looking downstream from Island Park Dam on January 6, 2025 after a fresh snowfall. How did Island Park winter flow shape up in 2025? Winter
Rob Van Kirk
March 7, 2025
General
How Much Snow Does Henry’s Fork Need for Average Streamflow?
And what does “average” mean, anyway? Now that we are about 75% of the way through the snow accumulation season, we have enough information to
Rob Van Kirk
February 21, 2025
Frequently Asked Questions
Water Year 2024 Technical Report
As most of you know, I started fishing the Harriman Ranch reach of the Henry’s Fork in 1977. I worked for Henry’s Fork Anglers from
Rob Van Kirk
February 10, 2025
Water Supply
Snow to Streamflow: A Story of Decline [Part 2]
Snow to Streamflow: A Story of Decline [Part 2] In snowy regions like the Henry’s Fork, the amount of water held in the snowpack on
Christina Morrisett
January 22, 2025
Water Supply
Snow to Streamflow: A Story of Decline [Part 1]
Henry’s Lake mountains, photo credit Sarah Newcomb Due to warmer growing seasons and denser forests, Henry’s Fork natural streamflow is declining and becoming less predictable.
Christina Morrisett
January 22, 2025
Research and Monitoring
FAQ: Is Outflow from Island Park Dam Higher Than it Used to Be?
Summertime outflow from Island Park Reservoir is lower (not higher) than it was in the “glory days”.
Jamie Powell
September 1, 2024
Water Supply
Mick & Mike Talk Henry’s Fork in the 1980s (VIDEO)
Mick Mickelson and Mike Lawson talk about the 1980s and what prompted the formation of the Henry’s Fork Foundation in 1984.
Jamie Powell
June 26, 2024
Water Quality
Rain Vs. Snow [Part 5]
Increasing spring and summer air temperatures have a doubly negative affect on water quality.
Rob Van Kirk
March 8, 2024
Water Supply
Rain Vs. Snow [Part 4]
Fish are affected by life-history specific streamflow and habitat characteristics that are not simple, direct functions of water supply.
Rob Van Kirk
March 7, 2024
Water Supply
Rain Vs. Snow [Part 3]
Water use + management in the Henry’s Fork watershed have much larger effects on streamflow than any changes due to precipitation type.
Rob Van Kirk
March 6, 2024
Water Supply
HFF Discovers Island Park Reservoir is the Center of the Universe
In recent years, HFF has expanded its work beyond the Caldera. Why? All roads lead to Island Park Reservoir, the center of the universe.
Christina Morrisett
March 6, 2024
Water Supply
Rain Vs. Snow [Part 2]
When snow makes up a larger fraction of total precipitation, prediction of irrigation-season water supply is more precise
Rob Van Kirk
March 5, 2024
Water Supply
Rain Vs. Snow [Part 1]
All precipitation is not created equal. Water supply is lower when a greater percentage of our precipitation falls as rain instead of snow.
Rob Van Kirk
March 4, 2024
Water Supply
Measuring streamflow on the Henry’s Fork: Why, Where, and How
In 2018, the Henry’s Fork Foundation began its Precision Management program. The motto for this program is “every drop, every day,…
Christina Morrisett
December 7, 2023
Water Supply
New Research by HFF Scientists and Interns
Summary. New research by HFF scientists and interns demonstrates how adopting center-pivot sprinkler irrigation over the last 40 years…
Christina Morrisett
September 20, 2023
Water Supply
Understanding SWE and Snowpack in Winter
What is Snow-Water Equivalent (SWE)? When it comes to how snow will benefit the river, looks can be deceiving. That’s why we report…
Jamie Powell
January 12, 2023
Water Supply
Changes to Lower River Management Benefit Upper River
Highlights: The lower river between St. Anthony and Parker is an important summer management lever for Island Park Reservoir. The Drought…
Christina Morrisett
October 6, 2022
Water Quality
Winter Flow Shows Increasing Trend
Winter flow at Island Park Dam is the single biggest management factor determining trout recruitment in the Henry’s Fork downstream of…
Rob Van Kirk
December 30, 2020