Sept 2018: Water Quality Monitoring – $11,000 funded by HLF

Excerpts from IDFG Fisheries Biologist, Jennifer Vincent’s Quarterly Report –

The lower than expected trout in the gill nets this year suggests trout may have experienced a higher than normal mortality rate over the last few years. Potential factor(s) limiting trout production in the lake may be temperature and oxygen. However, limited information exists on water quality in the lake.

As many of you may know the IDFG has partnered with the Henrys Fork Foundation, the Henrys Lake Foundation and the Idaho Department of Environmental Quality to implement a new sampling program to monitor water quality in Henrys Lake. Our first sampling date was August 7th and we have been out each week since.

What data are we collecting? We take water samples, zooplankton samples and collect water quality measurements at six different sampling locations. During the winter our water quality sampling equipment will remain deployed under the ice at one of our sampling locations allowing us to collect continuous water quality information throughout the winter. Water samples will be analyzed for total Nitrogen and total Phosphorus concentrations. We also collect data on dissolved oxygen (DO), temperature, conductivity (a measure of how much “stuff” is in the water column), and algal production (tied to the cyanobacteria blooms we’ve observed in recent years) as well as measuring water clarity. We collect zooplankton on a bi-weekly basis.

Our goal here is to gather information on the availability of zooplankton, which is used as a food source for Trout. This is important as we edge closer to the end of September, when we stock all our fish. Along with our partners, we will be evaluating our water quality monitoring program this winter to ensure we are collecting the appropriate data to monitor water quality and its impact on trout. More information regarding this project along with other current activities of the IDFG regarding Henrys Lake can be found at this PDF.


Feb 2015: IDFG 3-year Fishing Regulation Cycle Scoping Process

The HLF board recently provided input to the IDFG to curtail the ice fishing season and close the tributaries for the next 3 years. We know that this may not be a unanimous request but given the feedback that we have received it certainly appears to represent the majority of our membership. It is important that we take this opportunity to respond to the IDFG since it sets the fishing regulations for the following 3 years.

We encourage everyone who would like to offer their opinion or perspective to contact either Damon Keen or Dan Garren directly. You may recall that the decision to create an ice fishing season was first enacted in 2010. Since that time many anglers have experienced a decline in the number and size of the large hybrid trout. Although there is not absolute proof that the ice fishing has led to the decline in the big hybrids, the foundation board believes that it is contrary to our mission to protect and enhance the fishery of Henrys Lake. After all, Henrys Lake is considered to be a trophy fishery and a fishery like Island Park reservoir may be better suited for ice fishing. We believe that a 3-year hiatus in ice fishing may lead to an increase in larger fish and at a minimum provide the IDFG with another level of data for analysis. Again, we welcome everyone’s input on this very important request.


Aug 2013: Invasive Species Update

On Thursday August 15, 2013 an outreach program was held for water preservation and protection at Henrys Lake. It was hosted by Bryce Fowler from the Fremont County Weed Control department. Many other key organizations also attended, including Phil Barker and Larry Mcmillan from the Henry’s lake foundation.

It was an excellent opportunity to get up to speed on what it takes to protect our water resources and visit with the greatest of authorities on the issues. As you are all aware water is the single most important resource we have in Idaho. It is not only the key component to establishing and maintaining agriculture it is also brings in millions of dollars in recreation.

It was an excellent opportunity for the foundation to integrate into the aquatic protection arena as well as learn what is being done to protect this valuable resource and how to identify the desired aquatic ecosystem players and how to determine the possible invaders.

One of the single most authoritative figures in aquatic invasives management – Professor William (Bill) Haller from the University of Florida was in attendance. Bill was originally brought to Idaho many years ago to help Idaho build protocol for reducing the impacts of Eurasian water milfoil as well as our Invasive Species program such as the Quagga/Zebra mussle program.

Bill will be traveling with Tom Woolf, Idaho State Department of Agriculture (ISDA) Aquatic Program Manager, as well as Amy Ferriter (CPS) – former Aquatic Invasive Program Coordinator for ISDA. Our local contact for help from the ISDA is Matthew Kreizenbeck. He is located in Idaho Falls. He has volunteered to review any picture of suspected invasive specie that you may find. Simply email it to him at

Remember, it is incumbent upon everyone who uses any kind of watercraft or wades in our rivers and lakes to stop the spread of invasive species. Inspections can only do so much so the foundation encourages everyone to do their part.


Aug 2011: Record Project Year for the Henrys Lake Foundation

This year the foundation funded over $35,000 for fish passage improvement projects at Henrys Lake. This constitutes the largest single year financial commitment in the foundation’s history. Committed projects for 2011 include the installation of two new modular diversion screens on Targhee Creek and three new modular diversion screens on Duck Creek. All of these screens were designed and manufactured at the IDFG screen shop in Salmon Idaho and incorporate improved engineering for more effective maintenance free screening and fish passage.

In order to maximize natural reproduction of the Yellowstone Cutthroat trout it is essential that all irrigation diversions on the key tributaries of Henrys Lake be screened, ensuring that spawning adfluvial fish and fry don’t end up in an irrigated field. The first of the two screens for Targhee Creek was installed on the Salisbury property August 22 under the direction of Jim Hardy from the IDFG. The second and largest of the Targhee screens is planned for installation upstream on the Stockon property. With an HLF commitment of $17,500, it is the largest and most complex screen funded by the Foundation to date. With these new screens, all of the diversions on Targhee Creek, the major tributary to Henrys Lake, will be screened.

The first of the three Duck Creek screens planned for the Parkinson property was installed on August 23. The final two will be installed this fall. This will complete the screening of all diversions on this important tributary from Red Rock Road to the lake. The final HLF sponsored project for 2011 will be the removal of the double barrel culvert on Duck Creek on the Pearson property commensurate with the rerouting of Red Rock Road. This will return this section of Duck Creek to its natural pathway. This will be the last of the four culverts replaced or removed at Red Rock Road over the past two years.

Led by Lee Mabey of the U.S. Forest Service, this work on Red Rock road will eventually provide unobstructed passage for spawning fish to six miles of Duck Creek and its tributaries. As stated by Phil Barker, President of the Henrys Lake Foundation, “The foundation is extremely appreciative of the past support of its members and the community and takes great pride in its stewardship of the Henrys Lake fishery and positive results of its past efforts. It is only with the contributions and active involvement of our members, partners and community that the foundation can be successful. In that regard the foundation is continually seeking input of possible future projects that may provide benefit to the fishery and protection of Henrys Lake and the Yellowstone Cutthroat trout. If you are interested in joining the foundation, contributing as a volunteer or are aware of any opportunities that would enhance the natural reproduction of the Yellowstone Cutthroat trout, advance the Henrys Lake fishery, improve riparian habitat or otherwise protect the unique environment of Henrys Lake please contact the foundation at with your ideas.”


Jan 2011: New Year’s Day Ice Fishing Report by Bob Bartsch

Our family has for many years come to Island Park for the holidays and this season was no exception. Considering the amount of concern and discussion over the ice fishing season changes I felt that it might be helpful and important to have a past HLF Director as a first-hand observer.

I have done a small amount of ice fishing in Colorado in the past but really had no pre-conceived ideas of what I might see on Henrys that day. Some of my family had difficulty with car batteries, so I reached the Lake somewhat late, about 10:30 and met Damon at his house just after he did a 9AM angler count at and some interviews at Staley’s. We followed a protocol that the F&G established that called for an angler count at noon and then 4PM. We interviewed anglers before lunch and then from about 2PM until 4PM.

Carolyn and Damon provided a great lunch for the two enforcement men, Bill Schiess, a friend, and myself which allowed everyone to compare morning notes and observations.

1. How many fisherman were there? My estimate: somewhat over 300, maybe 325 maximum. Generally, they were in groups of 2-5, mostly men, but some women. I saw 3 families on the ice with children-most of the kids were playing, building snow forts and such. I suspect that the weather forecast discouraged the numbers of fishermen down from the larger crowd expected. The forecast for New Year’s morn was -26 degrees. At 6 PM on the 31st the temperature at my house was -6 already, but the skies clouded over and by 8PM the temperature had risen to +6 degrees. Most of Jan. 1 on the lake was clear with little wind until about 3PM. The temperature hovered from maybe -3 to +6 on the lake. When the wind started people left in droves. I was really surprised that folks were actually having fun and not freezing-as I was with my desert thermo-regulatory system. Then, again, Damon was perfectly comfortable at these temps also.

2. Where were they fishing? Maybe 3 groups could be seen through binoculars across the lake at the State campground and another 3 near the cliffs. These people must have gotten in via snowmobile as there was little road access available. The snow was up to 2 feet deep. The greatest congregation of fishermen was near the hatchery, followed by the County dock area, Wild Rose and finally Staleys. There were four groups fishing near Pin-tail point where the road to Staley’s is closest to the lake. I think these guys only caught and kept one fish; a 20″ brookie.

3. Where did they park their cars? Mostly they tried to get off the main roads into the hatchery lot or the County. We saw a few Sheriff citation stickers on windshields of cars parked on the main road at Staley’s and near the Hatchery but were not sure if they were only warnings. We spoke to a number of fishermen parked by Staley’s where there was a well-worn path over private property to the lake. Some of the men Damon warned about trespass moved on to the County. Parking and trespass may be an issue, but falls in the domain of the Sheriff.

4. Did I see any infractions of the fishing rules? Damon and I came upon three men who had four fish. When Damon asked who caught what, one man came forth and said something to the effect, “Oh, I caught two and I need to stop fishing don’t I?” He pulled his lines from the holes he had in the ice. Damon explained the infraction as a warning. This was the single infraction that we saw. Most fishermen had no fish and most groups only had one or two fish. The catch rate was very small. Everyone we talked with was friendly and cooperative. One or two mentioned that the enforcement was out in force that day. Several showed their licenses to Damon even though he had not asked to see them.

5. What were my impressions on the fish I saw harvested? A. The YCT I saw were nearly all 18 inches or larger. The average according to the measurements made was 19.2 inches and 20% were slightly larger than 20″. It was interesting that there were virtually no YCT caught or kept under 16″. I believe this was no anomaly of keeping larger fish and replacing smaller-earlier caught fish. People caught too few fish for this slight of hand to work. Most fishermen even in the summer do not catch many smaller fish for some reason. The important point here is that YCT generally do not live past their fourth year and, most that do live to four, die before the next summer. In the population of YCT there are only rare 5 year olds. Therefore, nearly all of the 172 harvested YCT would have died over the remainder of this winter and would not be available for fishermen to catch next season anyway. B. Few hybrids were in the creel-I was surprised how few we measured. C. There seemed to be a bias for brook trout in the creel-several mentioned that they felt they were better tasting. I saw no male brookies; only the females that represent the stocked sterile fish that the F&G plant. The largest I saw was a hair over 20″.

6. Could I characterize the fishermen? A. Most were very well equipped and pulled sleds out on the ice with their equipment. My impression was that these were confirmed ice fishers who enjoy a specialized fishing nitch. Maybe about 45-50% of the groups had tents on the ice. Many had heaters. Nearly everyone used those really short rods and most fishermen were using small meal worms or grubs that were on a hook just below a jig of some sort. They stood over the hole moving the rod up and down to impart action. Those with tents could see really well into the water and were able to see the take and set the hook in the upper lip of the fish. Only a handful were on snowmobiles or ATVs. The ice was very rough, wash boarded with drifts and even difficult to walk over. A snowmobile would have been a kidney-buster. How the two young men that were doing the enforcement survived their day on their snowmobiles, I do not know-had to be age related. B. It seemed that a few very knowledgeable ice fishers caught the lion’s share of the fish and most of these people released most or all of their catch. C. We saw very little abuse of alcohol and I saw no rubbish on the ice or in the parking areas. The exception was a man so drunk that when he emerged from his tent, he nearly fell on Damon to catch his balance.

Summary of the day on Henry’s. First, I believe this is a form of fishing that is exactly equal to the various other niche-types in the Yellowstone area seen in the summer: dry fly fishing on rivers or lakes, nymph fishing in rivers or lakes, spin casting, bait fishing, fishing from boats, tubes or rafts or wade fishing. The people we saw were well equipped by and large and really enjoyed their time on the ice. Killing fish was minor issue of those we saw on January 1; the release rate was 77.6%. People were having fun out on the lake that day. These are not folks from Arizona, California or other warm climes. They are mostly residents of Eastern Idaho who probably do a lot of ice fishing every winter-just like some people do across the upper mid-west.

Henry’s will come to represent for them a very special lake for ice fishing just as it has for many fishermen in the summer months. Most of the fish, the YCT, that were kept were at the end of their lives and would not be available to be caught next season. This fact negates any impact on the population of YCT in the lake.

Is it better to have ice fishermen harvest these fish or to allow them to die and decompose on the lake bottom? I asked a number of groups about their knowledge of HLF. Hardly anyone I talked to even knew there was a Henry’s Lake Foundation. They were impressed that we work with the F&G for the improvement of the watershed. These 300 some odd fishermen represent a population of possible HLF members. We need to have volunteers with membership forms out on the ice this coming fall and try to recruit these potential members.


Dec 2010: HLF Board Suspends Future IDFG Project Funds

In the quarterly IDFG commissioner’s meeting in Jerome, Idaho, on November 17-18, the commissioners voted unanimously to approve the extension of the fishing season at Henry’s Lake thru January 1. Along with the other IDFG proposals presented and approved all regulation changes will go into affect starting January 1, 2011 so the first extended ice fishing season will be December 2011 through January 1, 2012. Two other approved regulation changes that will directly affect us are 1).

The brook trout bag limit on Henry’s Lake tributaries was changed to 25 with only 2 brook trout over 16″, and 2) The season on the Henry’s Lake tributaries was extended from July 1 through March 31 with catch-and-release for cutthroat trout throughout the entire season.

As many of you know, we have actively lobbied to stop the season extension ever since we first heard about it in July 2009. Almost all of you voted unanimously in the fall 2009 newsletter survey to not extend the season and instead shorten it to the end of October as it was up until 2007. Our argument was that as the premier trophy fishing lake in the Western U.S. and as the last bastion of the Yellowstone Cutthroat trout, Henry’s Lake was deserving of special regulations to preserve that status.

While the Foundation has never lobbied against any type of fishing, it is our view that Henry’s Lake is a unique and fragile fishery and was due special treatment and that a season extension exposed the lake to inordinate trophy harvest and mortality by ice fishermen, particularly when nearby Island Park Reservoir provides ample ice fishing opportunity. In other words, we have a philosophical objection to the IDFG increasingly treating Henry’s Lake as a put-and-take fishery and more fully utilizing the resource while we envision it as a trophy summer sports fishery that needs to be protected.

HLF Director Steve Snipper and I were both in attendance at the meeting to offer our testimony. In addition, many Henry’s Lake anglers in attendance also spoke out against the season extension for the same reasons. Everyone advocated that the resource should be protected and that further liberalization of the regulations puts the fishery at even greater risk.

In opposition, the IDFG justified the season extension based upon fish population statistics claiming that additional harvest by ice fishermen will not adversely affect the fishery. In addition, they presented survey results that showed the majority of randomly surveyed anglers favored an extended season. Interestingly, our survey opinions were largely dismissed as being biased. Although the commissioners appreciated all the impassioned comments, they valued the biologic facts over our social and philosophical concerns. To say the least we are disappointed.

Our mission to protect and enhance the fishery at Henry’s Lake remains unchanged but we face a significant challenge with the IDFG continuing to liberalize the regulations in support of increased angler opportunity and simplification of the regulations – two of their stated strategic goals. Just as the IDFG extended the season in 2007 and then again this year, they may do it again in future years. We have no reassurance that they won’t and even told us so at the November meeting. So where do we go from here.

The HLF directors have voted unanimously to suspend funding of all future IDFG projects until further notice. The Board first suspended funding in October once we confirmed that the IDFG had finalized their proposal and was awaiting the vote of the commissioners. Although we have maintained a strong partnership with the IDFG for the last 29 years, it was too optimistic to think that our social and philosophical arguments would cause them to not extend the season.

I know they considered the consequences of losing our support when the season extension was first proposed but it was still not enough to stop them. Somewhat ironically they actually considered this a compromise since one of their proposals was to extend the season through the end of January. Given the IDFG’s liberalization of the regulations on Henry’s Lake both now and probably again in the future, the foundation needs to rethink its almost exclusive partnership with them.

Despite an excellent historic working relationship with IDFG Regional Biologist Damon Keen, the foundation will now focus on projects and funding opportunities that are not solely reliant upon the IDFG but still maintain our mission to protect and enhance the Henry’s Lake fishery.


June 2009: Remembering the Big One

Only two years ago I was immersed in the hustle and bustle of Silicon Valley in northern California, working as a software company executive traveling the world building large scale computer applications. With the corporate life now behind me, I can enjoy the beauty and grandeur of Henry’s Lake and the surrounding area each and every day. The view of the lake and the centennials every morning gives me quite a different perspective, one that is built upon history, people, and appreciation for this beautiful environment. Certainly not something I would have otherwise anticipated years ago in the corporate world.

As I think about the history of the Henry’s Lake Foundation and the yeoman’s efforts of this entirely volunteer organization and what it has accomplished over its 27 year history, I am drawn by a feeling of compassion, respect, and motivation. The goals set out by our founders were broad and comprehensive. They understood the importance of what needed to be protected so that future generations could enjoy the fishery. Not surprisingly the organization’s membership is passionate about these same goals.

The Henry’s Lake Foundation is guided by a board of directors with incredibly diverse backgrounds. They each bring their own unique perspective of priorities, benefits and ultimately stewardship of this incredible fishery. It is their collective input and wisdom that guides our project prioritization and funding.

It is very much a team effort with a balanced focus on natural production, hatchery production, water quality and fishery management. Much of what is accomplished each year by the HLF goes un-noticed by the majority of people who enjoy the fishery. Many folks have never even heard about us but as we continue to drive awareness it is important that our fund raising efforts adequately support our project endeavors.

The Henry’s Lake Foundation Day on the 4th of July at the Henry’s Lake State Park is one such event that is critical to our fund raising efforts. It is the generosity and support of the local merchants who make this event possible. I invite everyone to come out and meet the team and learn about what they can do to contribute to this great organization.

One of the greatest things about the Henry’s Lake Foundation is our partnerships with the related local, state and federal agencies. These partnerships make it possible for the foundation to leverage our monies raised with co-funding by these agencies. Central to driving these agreements is the Idaho Department of Fish and Game.

It is with the incredible efforts of individuals like Damon Keen, our resident fisheries biologist, that make our stewardship goals achievable. We are forever indebted to Damon and his team at the IDFG. When you are out on the lake trying to catch the big one, think about us. Realize that the big one is a possibility because of the efforts of the foundation. Hybrids are properly sterilized, protecting the native Yellowstone Cutthroat, because of the foundation. Brook trout stocking was successfully re-introduced in 2003 based upon the efforts of the foundation. The cutthroat egg take at the fish trap, over 4 million eggs annually, was made more efficient through the efforts of the foundation. Adfluvial fish migration during spawning season is enhanced through the riparian habitat improvement efforts of the foundation.

All of these efforts combine to provide an incredible fishery and place of recreation to be enjoyed by all. I wish everyone a tremendous summer with great fishing days and time to enjoy the beauty of this wonderful place, a place many of us can now enjoy for the rest of lives. If you want to get involved in the foundation, please visit our website at or call 208-558-9660. I look forward to meeting everyone at the picnic on the 4th of July at the Henry’s Lake State Park. Tight lines!


Jan 2009: Henrys Lake Winter 2008 Update by Damon Keen IDFG

As we head downhill towards spring, it is a good time to update the fishery at Henrys. With less than a month before the gates on the fish ladder are opened, all is well. I anticipate taking our hybrid spawn the last week of February – that is if the fish cooperate. Beginning the first week of March, the cutthroat spawn will commence and we will be working towards meeting our quotas. March through May we will be busy spawning, picking eggs, and shipping eyed eggs.

If you are interested in seeing lots of fish, the best month is usually March. We are here 7 days a week during that time-frame and you are always welcome. If you would like to volunteer, give me a call or shoot me an email. So far, the winter, moisture and water carryover bode quite well for the summer. We will be watching the moisture gauges the next couple of months, but so far, we are in good shape. The winter dissolved oxygen levels are holding up as well and we have not needed to deploy aeration. That is always good. I have also been corresponding with a biologist in Colorado with reference to critical winter dissolved oxygen levels.

It is a great resource to compare notes and I think both of us are gaining a good deal of knowledge. Ice out will see our annual gill net effort to determine our population trends of trout and non-game species. It is an all out effort, normally consisting of 8-10 nights of setting nets. We normally set a total 50 nets during that period and the data we gather is of upmost importance to the management of Henrys Lake.

With the number of nets we set, our data is statistically sound and gives us the best perspective of what is going on with the fish population at Henrys. It does not end during the spring however. The winter is filled with examination and more data collection of the fish we have collected during our spring gill net sets. Age class breakdown, annual growth, condition factor (weight relative to length), species composition, and diet are just some of the data we collect.

In the end, our intensive effort provides tremendous insight into the fish population at Henrys. We have a busy schedule of work plans for this summer. Several habitat projects will be completed and we will be conducting a major creel survey on Henrys.

Additionally, 2009 is the end of the two year regulation cycle and we will be conducting public meetings, scoping, and taking public input for the 2010-2011 regulation packet. I also hope to personally sample the fishery this summer. I have been reading the web pages for Henrys tips and maybe I will be able to land that 10 pounder this summer.

One to one correspondence is always appreciated and encouraged. If you have a question or would like to volunteer, feel free to call us at (208)558-7202 or email me at


Sept 2008: A Busy Week for the Henrys Lake Foundation

This past year the Henrys Lake Foundation (HLF) embarked on an aggressive plan to fund five fishery improvement projects for $30,000. All of our projects are conducted in partnership with the Idaho Department of Fish Game (IDFG) and other related agencies. The projects span natural reproduction, hatchery reproduction, fishery management and water quality. The first project of 2008 was in February when the HLF purchased a $7000 egg separator for the fish trap.

The new separator has two wheels and is significantly faster than the old separator and dramatically reduces the overall person hours needed to separate live and dead eggs. The tributaries of Henrys Lake continue to receive a lot of attention ever since the inception of HLF 26 years ago. During the week of September 22nd we completed the screening of the last lateral diversions on Targhee and Howard Creeks. These were key milestones given the importance of these two tributaries. Now we can be secure in knowing that the fry and spawning fish are safe from being accidentally diverted into the grazing pastures of the ranches bordering those key tributaries.

Our heartfelt thanks go out to the respective landowners, Ray Clements and partners and Tom Cole.

Our project work didn’t end there. Also during the week of September 22nd, we completed stream restoration efforts on the Empey property on middle Duck Creek and Kelly Creek.

The project work consisted of 4 different parts: the first was to fence the creeks running through the property so that grazing cattle do not erode the stream banks, the second was to raise the creek level below the head gate spillway on Duck Creek to improve fish passage and the third was to provide cattle watering areas by hardening a portion of each stream bottom.

The Kelly Creek project work also included the installation of a culvert so ranch vehicles and cattle can cross the stream in the pasture. In conjunction with the foundation’s stream restoration efforts on lower Duck Creek and Kelly Creek completed in prior years, the entire section of Duck Creek from the lake to Red Rock road and Kelly Creek from the lake to Henrys Lake road is now protected from grazing cattle. Over the next couple years the stream banks will be naturally restored with the growth of tall grazes and willows sheltering the waters edge.

The reduction in silt will expose the natural pebbles and stones in the stream bottom, providing an ideal habitat for adfluvial fish.

Our heartfelt thanks go out to the landowner, Debbie Empey, for supporting our efforts.

The week of September 22nd was also special in that the fencing work on Duck Creek and Kelly Creek was completed by inmates from the Idaho Department of Corrections in St. Anthony.

Under the direction of IDFG personnel, Kim Ragotzkie, Barry Phillips, Nancy Olson, and Paul Franco, the inmates worked hard digging post holes and stringing fence wire. The weather cooperated nicely and although the mornings started out a little chilly the afternoons were sunny and warm.

The work sites could not have been more picturesque with creeks running through golden pastures to the lake, the yellow and oranges of the aspens turning and the majestic mountains in the background. Throughout the week, the inmates were treated to lunches served by the directors of the HLF foundation.

Each director took a turn preparing the lunches and serving them at the job sites. Double cheeseburgers, chili dogs, fried chicken, club sandwiches and pizza were all on the menu. To say the least, the inmates loved the lunches and looked forward the next day’s menu items. The directors took it as an opportunity to express their heartfelt thanks to the inmates for helping to improve the Henrys Lake fishery.

HLF extends special thanks to the IDFG screen shop personnel from Salmon, Idaho. The team led by Jim Jones and Jim Hardy are the go-to source for the design, construction and installation of our self-cleaning screens. In addition to the installation of the 2 new screens on Duck and Howard Creeks they also performed maintenance on our 7 older screens while here during the week of September 22nd.

Following the completion of their work efforts, Damon Keen from IDFG, commented that the tributaries, from a fisheries management perspective, are now in the best shape they have ever been over the last 15 years! Next year will be another big year for the foundation from a projects perspective. Four projects totaling $30,000 have already been approved by the HLF board for funding.

The first project involves replacing the 20-year old self-cleaning screen on lower Duck Creek on the Taft property. The old wooden structure is beyond repair. Although small, the diversion is one of the most important on this tributary since it is the one closest to the lake. The second project is very similar and involves the replacement of the self-cleaning screen on Targhee Creek. Again the old wooden structure is beyond repair.

The new structure will be a double wheel design to support the larger seasonal stream flows. Note: all the new screens are all steel and should last more than 20 years. The third project is to replace the four culverts on Red Rock road where Duck Creek and Rock Creek pass underneath.

This project to improve fish passage is being lead by Lee Mabey from the US Forest Service and Marla Vicks from Fremont County. The old galvanized culvert pipes are in dire need of replacement especially those that are barriers to adfluvial fish migrating from the lake during the spawning season.

The fourth project is to install automated water temperature and flow sensors in Targhee, Howard and Duck Creeks so that a historical database can be compiled to monitor the flows of these tributaries in conjunction with natural spawn production.

By tracking these key tributary attributes, we will better understand the potential benefits of restocking the tributaries in conjunction with the stocking of the lake.

The Henrys Lake Foundation would like to gratefully acknowledge the participation of our partners that help make all our projects possible. They include: Idaho Fish & Game (IDFG) US Fish and Wildlife US Forest Service (USFS) Idaho Department of Agriculture Idaho Department of Environmental Quality (DEQ) Idaho Department of Water Resources Idaho Department of Lands Idaho Department of Parks and Recreation Idaho Department of Transportation Bureau of Reclamation Corp of Engineers (COE) Fremont County Fremont County Weed Control National Resource Conservation Service (NRCS) You can visit the foundation website for further information on how to become involved in these projects and associated fund raising efforts.


Jan 2008: Aeration at Henrys Lake Winter 2007/08

From Damon Keen IDFG.

I’ve had several questions regarding aeration at Henrys this winter and namely, “Why isn’t the F&G running the aerators?”

First off, identifying what the aeration system is supposed to do is necessary. The aerators on Henrys were installed in the early 1990’s, shortly after a winterkill event that was caused by low dissolved oxygen levels in the lake.

The system consists of 12-2″ PVC lines that fan out in front of the hatchery ladder and are located in staggered positions as far out as 400 yards from shoreline. At the end of the PVC lines aeration heads are attached. The system pushes air through these lines with the means of a 20hp electric motor attached to a large blower. When the system is running, the result is that air is forced through the lines, out the aeration heads, and a fountain of air bubbles to the surface above the heads.

The bubbling action brings warmer water from the lake bottom to the surface, where ice is melted. The newly formed open water can then be recharged with oxygen from the environment.

The system cannot recharge the entire lake with dissolved oxygen. Henrys is a large lake and the impacted area is relatively small. The system was designed to improve dissolved oxygen content in the immediate area of the hatchery. In the event of a major oxygen depletion event, the goal is to improve dissolved oxygen content enough so springtime spawning can be successful.

In the event of a major winterkill, the objective is to at least have sufficient eggs to restock the lake the following fall. Along with improving egg quality, our radio telemetry study in 2007 showed adult trout move along the shoreline during the winter making them more likely to encounter our aerators, which may help survival in stressful times.

Fortunately, with the data and research completed during the early 1990’s by Tom Herron, we have an excellent understanding of what to expect during the winter at Henrys Lake. Dissolved oxygen levels are monitored at several locations shortly after ice forms on the lake.

Monitoring is repeated at intervals and an evaluation is then made to determine if aeration should be deployed. Basically, the data collection points enable us to predict if sufficient dissolved oxygen levels will prevail until ice leaves the lake and natural recharge begins. This method of evaluation allowed us to predict early during the winter of 2003/04 that dissolved oxygen levels could become critical prior to ice off. Therefore, aeration was deployed. Fortunately this winter (2007/08), current dissolved oxygen levels remain good. And although evaluation is ongoing, to date (1/10/2008) aeration is not necessary and the aerators remain idle. The Idaho Fish and Game deploys aeration on poor or marginal dissolved oxygen years. However, winters where sufficient dissolve oxygen levels are present, the aerators collect a little dust. And that’s good.