The Caldera Project

_{By STEVE TRAFTON}

The Henry's Fork watershed is big and diverse, stretching from the Continental Divide to the Snake River Plain. To thousands of anglers and river lovers "the Ranch" – the nine-mile stretch of river flowing through Harriman State Park – is both the heart and the soul of the river. It has been a staple of fly fishing writing and lore for more than 30 years, but in recent years the big rising trout upon which the Ranch's fame rests have been, by many reports, in short supply.

With this in mind, this spring the Henry's Fork Foundation began the Caldera Project, a broad investigation of our current scientific understanding of the caldera reach. HFF is conducting research to further that understanding, gain a better understanding of the angling experience, and figure out what we can do, beyond our ongoing emphasis on flows and reconnecting habitat, to preserve and improve the fishery.

Although the Ranch is the focus of interest of most concerned observers, the research component of the project will examine the entire river reach, including tributaries, from the upstream fish barrier at Island Park Dam to the downstream barrier at Mesa Falls. The project's first year will include the following elements:

Literature review. A significant body of research, much of it led or inspired by the HFF, exists for the waters between Island Park Dam and Pinehaven. Biologist and consultant Jim Gregory will review all existing research that has bearing on the Ranch and its fishery to provide us with a focused perspective on what we know about the Ranch, and also what we do not know about how the Ranch fishery works. This will allow us to make informed decisions about future research, restoration, and management options for the fishery. We will also produce and distribute a brochure that will provide a layman's synopsis of Gregory's review.

Buffalo Dam outmigrant trap and monitoring. Fish passing upstream through the new fish ladder at the Buffalo Dam are currently being trapped and counted, and as a result we know that the ladder is fully functional. What we do not know, however, is how many fish pass back downstream over the dam. Thus we cannot quantify one of the key assumptions driving fisheries management below Island Park Dam -what is the Buffalo River's role in the health of the wild trout fishery in the Henry's Fork? We will construct, install, and assist in the maintenance of an outmigrant fish trap for the Buffalo Dam in order to test the truth of the theory that, except for improving winter flows, reconnecting the Buffalo River is the single most important guarantee of an improved and maintained Ranch fishery.

Population estimate. The Idaho Department of Fish and Game, supported by HFF, will conduct an electrofishing survey of the Ranch. We cannot predict how effective this will be due to the physical characteristics of the river in Harriman State Park that make fish sampling extremely difficult. If the effort bears statistically significant results, however, that information will answer one of the fundamental questions for which we currently have no answer: How many fish are there in the Ranch right now?

Creel and angler satisfaction survey. Public interest in the state of the Ranch's fishery is driven virtually entirely by the public's interest in the state of fishing on the Ranch. A concerted effort to understand the fishery needs to be augmented by a parallel effort to understand the angling experience on the Ranch – if nothing else because a healthy fishery does not necessarily produce satisfied anglers. By the same token it is possible to create excellent fishing opportunities in waters that do not support healthy fisheries. Although the IDFG does not normally conduct creel surveys on catch-andrelease waters, it has committed to a creel survey on the Ranch in 2008 to gauge angler effort and success. HFF will work with the IDFG to gather complementary information on the Ranch's angling experience.

Caldera Web site. The Foundation will maintain a Web site dedicated to this project, complete with angler survey and related field data and photographs updated several times each week, links to the Gregory literature review and associated research, and other information. The site will be our attempt to engage the public's attention, and to maintain its interest, in the history, current status, and future of the Caldera fishery.

The HFF survey crew is now on the river and at the Ranch access sites talking to anglers and collecting data. Please talk to them, and if you encounter them on more than one occasion give them an update on your experiences. The angler survey is vital to the Caldera Project's success, and we depend on anglers to give honest and accurate information.

The Caldera Project Web site can be reached via a link on the HFF's main Web site -www.henrysfork.org.

The HFF could not undertake the Caldera Project without the generous support of the Ishiyama Foundation and the Marine Ventures Foundation, our longstanding partnerships with the IDFG and Harriman State Park, and, most important, the public's participation. Please watch this space for updates.

This is part of the online edition of Henry's Fork Country.

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