The 2019 Season on the Harriman Ranch

The 2019 season provided periods of excellent fishing. My clients and I landed 149 good rainbows in 513 hours on the water. (From this point forward each time I address a “rainbow” or a “fish” it will be a rainbow trout of at least 17 inches in length.) Every fish was landed on a dry fly.

We had superb Green Drakes, and Flav fishing in June and early July. I found Green Drakes in better numbers than I have for years. We landed 19 rainbows on Green Drakes in 2019. That compares to 20 landed in the seven proceeding years. The Flav fishing, while often very difficult because of very low, clear water, still produced 10 fish on Harrop no-hackle duns. That is twice as many as landed in any other year since 2012. We also had a couple of excellent Brown Drake evenings.

The terrestrial fishing was very good and the hopper fishing was excellent. It began in late July and remained productive until the middle of September. My clients and I landed 56 rainbows on hoppers while exclusively walk-wading. Some Ranch anglers are disrespectful of those of us fish hoppers, saying it is too easy and requires no skill. I shall argue that to be successful takes relentless determination, the ability to make accurate, long casts with both hands, the skill to get good drifts, the need to select highly realistic grasshopper flies, the experience to effectively play fish while wading, and a measure of physical toughness. If someone you know thinks it is easy, ask them to join you for five consecutive hours of blind casting, while wading, on a hot afternoon. My guess, and it is an educated guess, is they will make an excuse to quit in less than two hours. For the angler who says, with righteous indignation, “I never fish hoppers because the big hooks will injure our rainbows,” I will respond that my clients and I fish only size 12 hoppers. Ask the righteous guy why he has no problem fishing size 8 Brown Drake duns.

Our remarkable flying black ant fishing was good all summer long. Our honey ants were not seen in the quantities we have had in other years, but the one day I found them, I hooked nine fish and landed six. A continuing mystery concerning terrestrials is that the black beetle, which was highly productive in my early years on the Ranch, produced only one rainbow in 2019.

I deem a day when I, or a client, land three rainbows as excellent. In 2019, we had twenty days of three or more rainbows landed. A few clients had remarkable days. Dr. Randy Shannon took a spectacular 23-inch rainbow on a Harrop Green Drake emerger. For those who have heard exaggerated reports of fish of 23 inches or longer, the total number of rainbows my clients and I have landed that have been at least 23 inches long over my thirty-seven years of fishing and guiding is only 28, and the longest was 24.5 inches in length. That is out of a sample of 2,258 rainbows of 17 inches or longer.

Two other clients had great days. On two days, 8/6/19 and 8/8/19, Paul Bente landed five rainbows on hoppers. On 8/14/19, Brent Benjamin had no less than 20 rainbows come to his hopper on a day that was so good we passed up lunch. Brent hooked eleven fish and landed four.

Two good friends also had great days fishing with me when I was not guiding. On 8/10/19 Chip Westerman and I hooked 12 fish on hoppers and landed 5. A special feature of the day was that two of our fish were over 20 inches in length. Matt Barber, one of the owners of Tom Morgan Rodsmiths in Bozeman, landed three rainbows out of only five hooked on 8/13/19. Landing three out of five rainbows is an impressive average on the Ranch.

As I reflect on the 2019 season, I remain impressed with how resilient the river is. The recovery of insects and fish, in a year, was remarkable. I am confident it was a function of the natural precipitation and cool temperatures we got during the winters and springs of 2017- 2018 and 2018-2019. It was astounding how quickly some insects and fish came back. By fish, we are talking about the remarkably higher number of heavy, strong 15 to 17-inch rainbows we encountered in 2019. The recovery of our Green Drakes was no less than incredible. We had not had any Green Drakes in recent years that were close to those we enjoyed in 2019. My clients, or I, encountered wonderful hatches on the following dates: 6/28, 6/29,6/30, 7/1,7/2,7/3,7/4,7/5, and 7/6. I do not remember a time in the last 20 years when I had as many days with Green Drakes.

Despite the highly productive Green Drake and Flav fishing in June and early July, we had modest dry fly fishing with aquatic insect imitations until September. The one exception was when anglers found good numbers of fish eating PMDs in areas below springs where the water was cool. Those of us who did not want to deal with, or impose our clients to, the crowds near Osborne Springs or the Wood Road, were highly dependent on hoppers during the entire period from the last week of July until early September when we began to have good hatches of Trico duns and Blue Wing Olives, and a few Mahogany duns.

The number of rainbows landed of 20 inches or greater in length was significantly reduced in 2019. From 1983 through 2018, 709 rainbows, or 33.6 percent of all, 2,109 fish landed were at least 20 inches in length. (I would love to know how the 33.6 percent of fish compares with resident, wild, trout taken on dry flies on any other river in the world.) In 2019, only 29, or 19.4 percent, of the 149 rainbows we landed were at least 20 inches long. My data on the reduction in fish of 20 inches in length was not an idiosyncratic finding. A good friend, and skilled angler from the East, Mike Danko, did not take a 20-inch fish in a week of fishing. It is the first time since Mike began fishing the Ranch in the early 1980s, that he did not land a 20-inch fish, and he has rarely missed his annual trip.

I do not share the optimism of some friends who say, “The future of Ranch fishing looks wonderful!” The implication of that statement is that two good years of precipitation and cooler temperatures in the winter and spring assures the future will be superb. Don’t forget, we do not have any guarantees of water releases if we have a couple of very dry, warm winters and springs. Two bad years of weather can take us back to terrible fishing. The improved Ranch fishing of 2019 was exclusively the function of “good” weather at critical times. That is simply good luck; moreover, climate change studies indicate a repetition of the cool, wet weather is unlikely.


In the last eight years there has been a dramatic alteration in the productivity of dry flies that imitate aquatic insects as compared to terrestrial insects. The variations came to my attention when I began to compare the results of my fishing since my Ranch book was published in 2012. The data from the period, 1983—2011, contrast dramatically with the second period of 2012—2019. The following two tables document the six most productive flies from both periods. I recorded the data for each day of my fishing and guiding for the consecutive years of 1983 through 2019. During those thirty-seven seasons, I fished or guided on the Ranch for 13,445 hours.

It is eminently reasonable for the reader to ask if the productivity of the respective flies was impacted by how much I fished them. I reject the, “he simply fished some flies more” explanation. Satisfying clients on the Ranch is not easy, and to achieve a measure of success, a guide is compelled to use flies that have the best chance of deceiving our rainbows. I believe it is relevant to add that it was difficult for me to not rely on the aquatic dry flies, like PMD duns and adult caddis patterns, that had been highly productive in the 1980s and 1990s. If I had been clever enough to see how much more productive terrestrial flies would become earlier in the period of 2012—2019, the documented variations I shall present between the two types of flies would be more impressive.

The following tables provide data on the six most productive dry flies imitating aquatic and terrestrial insects for the two periods of my fishing and guiding. Table One identifies the most productive dry flies for the period of 1983 though 2011. Table Two will address the most productive flies for the period of 2012 through 2019. I shall add that the numbers articulated for all the fish landed during the respective periods—1,523 in the first period and 735 in the second address all the fish taken during the period. When I focus on the percentages of fish taken by the flies imitating aquatic as opposed to terrestrial insects in the respective period, I will use the sum of the fish that are on the two lists. That total for the six flies on the 1983-2011 list is 805 fish, and for the second period it is 454.
1- Pale Morning Duns = 186 or 12.2 % of all 1,523 rainbows.
2- Flav Duns = 137 or 8.9 % of all 1523 rainbows.
3- Honey Ants = 129 or 8.4 % of all 1,523 rainbows.
4- Caddis Adults = 125 or 8.2 % of all 1,523 rainbows.
5- Black Beetles = 115 or 7.5 % of all 1,523 rainbows.
6- Rusty Spinners = 113 of 1523 or 7.4% of all 1,523 rainbows.
1-Grasshoppers = 193 or 26.2 % of all 735 rainbows.
2- Flav Duns= 64 or 8.7% of all 735 rainbows.
3- Black Flying Ants = 59 or 8.0% of all 735 rainbows.
4- Honey Ants = 52 or 7.0 % of all 735 rainbows.
5- Calliebaetis Spinners= 46 or 5.8 % of all 735 rainbows.
6- Mahogany Duns = 40 or 5.4 % of all 735 rainbows.


Of the list of six most productive flies from the period of 1983 through 2011, four of the flies—PMD duns, Caddis adults, rusty spinners, and black beetles did not make the list for the 2012-2019 period. The four flies that imitated aquatic insects: PMD duns, Flav duns, Caddis adults, and rusty spinners provided 561 fish, or 69.6 percent of all the fish, 805, taken by the six most productive flies. The two terrestrial flies on the list, the honey ant and black beetle provided 244 fish or 30.3 percent of all the rainbows taken.

There were four new flies on the six most productive fly list for 2012-2019. They include grasshoppers, black flying ants, Callibaetis spinners and Mahogany duns. The number one fly on the 1983-2011 list, the PMD dun, did not make any of the top six positions on the 2012-2019 list and dropped in productivity from 12.2 percent of all rainbows landed to 3.6 percent on the second list. The adult caddis flies also failed to make the second list and declined, from taking 8.2 percent of all fish to 1.8 percent.

There were 150 rainbows taken on the three aquatic flies on the 2012—2019 list: Flav duns, Callibaetis spinners, and Mahogany duns. The 150 fish represent 33.0 percent of all the rainbows, 454, taken by the six flies on the list. In the context of the productivity of terrestrial insects, there were 304 fish taken by: honey ants, flying black ants, and grasshoppers. The 304 rainbows represent 66.9 percent of the 454 fish.

The disparity in the productivity of the aquatic as opposed to terrestrial flies when addressing the top six flies for the two periods are dramatic. In the first period, the aquatic insects provided 69.6 percent of all the fish. In the second period, the aquatic insects produced 33.0 percent of all the fish. In the first period, the terrestrial insects produced 30.1 percent of all fish. In the second period, the terrestrial insects produced 66.9 percent of all fish.

Another provocative finding was that two flies maintained a high level of productivity over the entire thirty-seven-year period. One was the Flav dun. The Flavs were responsible for 9.0 percent, or 137 of the total of 1523 rainbows landed in the first, 1983 through 2011 period. In the 2012- 2019 period the Flavs were responsible for landing 64 or 8.7 percent of the total of 735 rainbow taken in the second period. Why did the Flav duns remain remarkably consistent during the two periods? The nymphs of the size 14 mayfly are rock clinging and exploit similar habitat as the PMDs. It would be fascinating if only mayflies with burrowing nymphs had been reduced in numbers; however, in this case the Flavs and the PMDs—unlike Brown Drakes, who, with their burrowing nymphs, are found in much higher numbers in areas of the Ranch with river bottom of silt, or mud—are occupying similar micro-habitats.

The other fly that maintained comparable productivity for both the 1983 though 2011 and 2012 through 2019 periods is the honey ant. As all experienced Ranch anglers know, the fly is as likely to make our rainbows aggressive feeders as any other. In the early period, the honey ant produced 129 good rainbows of a total of 1523 landed or 8.5 percent. In the 2012 through 2012 period we took 52 rainbows on the honey ant or 7.0 percent of the 735 fish we landed. Like the Flav, the honey ant seems to be immune to whatever the factors were that reduced the productivity of PMDs and caddis flies.


I do not have definitive answers as to why the alterations in our populations of aquatic as opposed to terrestrial insects took place; however, after interacting with many anglers, fishery biologists, and conservationists, I shall articulate what appear to be logical reasons for the significant changes.

My first clues as to what might be influencing the variations in populations of aquatic as opposed to terrestrial insects were provided by fishery biologists and conservationist at meetings in Bozeman, Montana. I was shocked by the emphasis placed on climate change and the implications of the increasing water temperatures seen in the state’s rivers. Researchers at one meeting presented data that indicated that temperatures in the Yellowstone River were rising so rapidly that smallmouth bass were migrating into upper stretches of the river where they had never been seen before. In addition, several of the fishery biologists said they were seeing declines in aquatic insects. One speaker said he was specifically seeing significant declines in caddis species and PMDs. I was shocked by the comment, as I had assumed the declines, I had documented in PMDs and Caddis were specific to the Henry’s Fork.

As I extended my interactions on the subject with anglers from other parts of the country, I encounter others who were coming up with similar findings. I came to the conclusion that the following factors have probably been relevant in decreasing the numbers of aquatic insects on the Harriman Ranch. First, are chronically poor winter water flows from Island Park Reservoir. The catastrophic impacts of poor flows in the winter were defined by research either conducted by, or supported by, the Henry’s Fork Foundation. The organization deserves great credit for initiating that critical work. The impact of poor winter flows was exacerbated by alterations in flows during the summer months, particularly in July. It is now clear that the heavy flows in July do not result in the significant removal of silt sediment as would be the case if similar quantities of water were released at other times of the year. (The heavy July flows are dictated by agricultural demands.) The heavy flows from Island Park Reservoir also create more turbidity in the water. In some cases, as in 1992, releases of water made when the levels in the reservoir were very low, caused massive amounts of silt to be deposited throughout the Ranch. The catastrophic implications of poor winter flows, alterations in flows, heavy flows in July, and massive accumulations of silt from the Reservoir have been compounded by the myriad implications of climate change. It is clear that climate change has caused higher water temperatures, increased vegetation growth, and the proliferation of algae.

Ironically, climate change appears to have been beneficial to some insect populations. The significantly higher productivity of flies imitating terrestrial insects has probably not only been a function of their being immune to the deteriorating aquatic environment, but also a result of some terrestrial species benefitting by increased temperatures and dryness. I am confident those factors have enhanced grasshopper populations.

The fact that the black beetle declined in productivity in my second period, 2012-2019, is the one contradiction in what has transpired with terrestrial insects generally. I believe the beetle decline can be explained by the fact that during the early, highly productive beetle period of 1983—1990, many of the insects were attracted to diseased conifer trees on, or near, the Harriman Ranch.


I believe that warming water temperatures on specific sections of the Ranch are stimulating rainbows to exit the areas for periods of the season. The factor stimulating rainbows to leave some areas and not others is probably their varying distances from springs providing cool water. One of my favorite sections of the Ranch is the Channels and The Flats Above the Channels. Since 2015, many large fish move out of the area from mid-July to late August or early September. I am confident that the fish migrate to other sections of the Ranch, or other sections of the river beyond the confines of the Ranch, that maintain lower water temperatures. One fact that may be relevant to the higher water temperatures in the Channels is there are few springs upstream from the Channels or flowing directly into the area.

In the context of the implications of warmer water temperatures, I am confident the excellent fishing on the Woodroad in the heat of the summer of 2019 was a result of cool water being released by significant springs above the area. Three critical sources would be Big Osborne Springs and the two Gravel Pits’ Bay Springs; in addition, there are other springs in the river, or that feed into the river, between Osborne Bridge and Pinehaven.

For the reader who does not realize that our whitefish have declined precipitously, in the eight seasons since 2011, my clients and I have landed 735 rainbows and one whitefish. In contrast, I have a journal entry from 1989 that indicates that on 20 June, I hooked and landed six whitefish before I was able to get a rainbow to take my Brown Drake emerger. It was common to have whitefish keep you from getting your flies to rising rainbows in the 1980s.

In August of 2019, I had an experience that convinced me the lack of Ranch whitefish may be related to increasing water temperatures. I was walking up the north bank of the river from The Islands to Antelope Spring Creek when I encountered a tiny creek that entered the river. As I easily stepped across the flow, I saw two whitefish holding in the water. (They were the only whitefish I saw in 2019.) The fish darted out into the river. The temperature of the water in the spring creek was 52 degrees. The temperature in the river, two feet upstream of where the creek entered, was 64 degrees. I had not questioned the concept that the reason we had such a dramatic reduction in our whitefish was because of the reduced water quality, and other negative implications, of the huge deposits of silt we suffered with the catastrophically low draw down of the Reservoir in 1992. Now, I suspect the incremental increases in water temperature have probably contributed to whitefish mortality, or their relocation to cooler sections of the river. I am confident that our native whitefish have been “canaries in the mine” for the Ranch fishery.


I have seen a dramatic reduction in the number of honey ants in the Channels. In 2014, 2015, and 2016, I averaged 9.5 days of productive honey ant fishing in The Channels, and Flats Above the Channels each year. In glaring contrast, in 2017, 2018, and 2019, I averaged only 1.5 days a year of honey ant fishing. What makes the numbers impressive is that fishing in other areas of the Ranch produced more rainbows in the years of 2017, 2018, and 2019, than in 2014, 2015, and 2016. (No less than 99 more rainbows were landed in the years of 2017—2019.)

There has been a significant decline in Callibaetis spinner fishing in the Channels from 2012 through 2015. My clients and I took 29 good rainbows on flies imitating Callibaetis spinners during the four-year period. In contrast, in the four years of 2016 though 2019 we landed only 14 rainbows when using the size 14 and 16 spinners.

My recent interaction with anglers and researchers across the county who are stressing the impact of climate change on many different fisheries, stimulated me to ask: why does The Henry’s Fork Foundation not articulate more concern about climate change? I made the decision to carefully re-read the literature I had received from the organization, as a life member since the 1980s, to see how often I encountered the words climate change. I had, randomly, saved ten publications since 2017. They included eight issues of the “Voice of The River Newsletter” and two issues of the “Foundation’s Annual Report”. I did not find the two words, “climate change” in any of the publications. What made my finding provocative was that at every meeting of fishery biologists, anglers, and conservationists I attended in Montana the subject of climate change was addressed more frequently than any other subject.

Why is climate change being ignored by the Foundation? I have addressed that question to friends who are board members of the organization. Their answer was that the study “is beyond the capacity of the organization to address.” The answer is unsatisfactory. I worked with research most of my adult life. My Ph.D. is not in fisheries biology; however, an analogy in my field would be if one were investigating the evolutionary implications of the disease of malaria to human populations in Africa but denied the opportunity to study the role of the mosquito to the etiology of the

disease. Anyone with even the most elementary knowledge of malaria would say the failure to address the critical role of the mosquito would make any other work undertaken worthless.

Is it reasonable to suggest that climate change should not be studied when your goal is to protect and enhance the Henry’s Fork in the year 2020? My position is if we do not address the role of climate change, and aggressively support all efforts made to support climate research, we are not doing what we should to protect the river.

I think it is imperative that all those concerned about the health of the Ranch fishery, be ready to listen to anglers, not simply researchers with PhDs. Many of the most insightful, and prescient comments concerning the health of the Ranch fishery have come not from those with PhDs, but experienced anglers who love the river. To support that point, as a board member, in the 1980s, I voted, along with a majority of the board at the time, to help Trumpeter Swan populations on the Henry’s Fork. Rene Harrop approached me and challenged the idea of investing time and money in support for the iconic birds rather than focus exclusively on the health of the fishery. His argument included the fact that the swans consumed huge quantities of aquatic vegetation that, at the time, was declining on the river. I remember being embarrassed that no one on the board had challenged the idea of directing time and money to the swans. The point is that none of us had the insightfulness or knowledge of the river that Rene had, and has.

When we began to have critical problems with the irrigation canal at the Top of the Ranch—and as a guide running walk-wade trips, it was very difficult to explain to every client why the area between the parking lot and the river was a quagmire, and why we would find dead rainbows in the canal. (For the record, that took place for well over a decade before any efforts were made to address the problem.) It was John Wilbrecht, an angler, who insisted something had to be done. He wrote a paper on the problem, took pictures of dead rainbows in the canal, and, most importantly, was relentless in arguing the situation had to be addressed. Those of us who fish the Ranch for hundreds of hours each season know he alone was responsible for the Henry’s Fork Foundation finally implementing work on the canal.

My point is: do not assume a person with a Ph.D. will have all the answers. Many are arrogant, some are lazy, and a few lack integrity. Look for answers from men and women, who have the passion, determination, and integrity of Harrop and Wilbrecht. When you find them, listen carefully to what they say. In addition, support all research and efforts being made to address climate change, and support all politicians who see addressing climate change as a critical national goal—if we do not, no other efforts, no matter how well funded, will allow the incomparable Ranch fishery to survive for long.


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