PROSPECT — Justin Miles slogs down a small creek that flows into the North Fork of the Rogue River when a wet step reveals one of the underwater denizens he's seeking.

PROSPECT — Justin Miles slogs down a small creek that flows into the North Fork of the Rogue River when a wet step reveals one of the underwater denizens he's seeking.

A 15-inch brown trout digging a spawning nest in the creek's gravel is surprised by Miles and darts for cover, causing Miles to reach for his notebook.

"Whoa, that's awesome," says Miles, noting the fish and its location on an Oregon Department of Fish and Wildlife data sheet. "I haven't seen one that big in here. Obviously, it's a pretty fish."

One sloshy step for Miles is one flash of new light now shining on resident trout in a portion of the upper Rogue River near Prospect, where trout populations have been largely ignored for decades.

Miles is spearheading the first comprehensive survey of trout living in the far upper reaches of the Rogue upstream of Lost Creek Reservoir. The project is meant to improve trout populations here and potentially expand angling opportunities for them.

Funded by PacifiCorp as part of its federal relicensing of Prospect-area hydropower projects, the survey seeks to estimate how many of the two native and two exotic trout species live in these cold streams, as well as what habitat exists for them and what impediments curb their distribution.

The information will be summarized in a report that biologists say will guide habitat enhancement efforts in that region over the next decade, as well as highlight where angling access can be improved with such things as fishing trails.

The result could be a better-understood and better-used trout fishery — similar to some streams in Central Oregon — smack dab within the heart of salmon and steelhead country of Jackson County.

"It's a really exciting project to do good things for trout above Lost Creek," says Dan VanDyke, the ODFW's Rogue District fish biologist. "That area up there is what I consider to be our prime summer trout fishery. There's no ifs, ands or buts."

The Rogue is the region's signature coastal stream, with waters downstream of the reservoir generating more wild salmon and steelhead than any Western Oregon stream outside the Columbia River.

But the waters upstream of the dam have no salmon or steelhead and largely have been ignored by biologists, except for a study on pockets of trout done there in 1979-80.

Those surveys showed the area was home to native rainbow and cutthroat trout, as well as remnants of nonnative brown trout and brook trout introduced there and elsewhere in the West decades ago.

Portions of the Rogue are stocked regularly with hatchery rainbow trout between Memorial Day and Labor Day for anglers. Resident fish tend to be smaller, a result of expending so much energy eking out a living in the cold water there.

Brook trout thrive in cold water and likely are relatively larger and more broadly distributed than other species, VanDyke says. But to what extent has remained a mystery.

PacifiCorp's relicensing process has created an opportunity to shed light on these fish.

As part of relicensing negotiations, the ODFW haggled with PacifiCorp over how to ease abrupt fluctuations in river flow in a two-mile stretch of water immediately upstream of the reservoir during intermittent power outages at the plant.

The agency insisted the utility install a multi-million-dollar valve system to curb those abrupt flows, says David Harris, an ODFW biologist who works on hydropower relicensing issues in southwest Oregon.

Instead, the two sides negotiated a side agreement in which PacifiCorp created a so-called "Resident Trout Fund" that will pay out $1 million over the next decade.

The fund is dedicated to covering the costs of several research efforts — and even some potential habitat projects — within the trout waters in and around those Prospect-area diversions.

The work began in October when Miles and cohort Heather Lundgren began surveying the North Fork, as well as various tributaries such as Schoolma'am Creek, a tucked-away forest rivulet that flows into the project's North Fork Reservoir.

The pair scale steep slopes and wiggle through thick swaths of vine-leaf maple in order to eye the underwater gravel for signs of spawning nests, called redds.

One redd, already flagged with pink tape so it won't be counted twice, is about the size of two fists together.

"That one moved a lot of gravel, so you can tell it was a pretty big fish," says Miles, who has counted five brown trout redds in the creek's lower reach this month.

Brown trout are spawning now, while brook trout and rainbow redds were counted earlier. These counts will be followed by surveys for cutthroat trout.

"We'll keep coming back here until they're done," Miles says.

Other facets of this project include surveys to gauge when baby fish emerge from the redds, as well as migration patterns and abundance of juvenile fish.

The results are expected to help VanDyke in various ways, such as identifying places where culverts block trout from spawning grounds, and in the creation of angling maps that point anglers toward species they desire, VanDyke says.

It also could lead to new trails, improving access to fishing hot-spots that sport little or no access now.

"Out of this, we'll get a summary that will guide habitat work and potential fish-restoration projects," VanDyke says.

Reach reporter Mark Freeman at 776-4470, or e-mail at mfreeman@mailtribune.com.