BOISE, Idaho — To spawn in Little Bear Creek's west fork, wild steelhead must run a hazardous, 500-mile gauntlet up the Columbia, Snake and Clearwater rivers from the Pacific Ocean that includes sea lions and anglers' lures.
But when they arrive each spring in Troy, a logging town where north-central Idaho's rolling Palouse Hills meet the mountains, a 93-year-old dam blocks all but the strongest fish from reaching the stream's headwaters where, until 1919, they'd laid eggs for thousands of years.
The Dutch Flat Dam, originally a city drinking water source, hasn't even been used since 1926, when silt choked the creek.
This summer, however, town leaders, farmers and state biologists aim to demolish the 10-foot-high barrier and restore the creek to a more-natural state to give its steelhead a better shot at producing Idaho's next generation of oceangoing rainbow trout. It's the latest U.S. dam removal project, including destruction of the much-larger Elwha Dam on Washington's Olympic Peninsula, undertaken to give fish listed under the federal Endangered Species Act a fighting chance at recovery.
"What's really amazing is that those fish were so tough to make it, without being able to go by the dam for so many years," Troy Mayor Ken Whitney said. "Hopefully, we're going to help them out a bit."
Little Bear Creek's steelhead have been listed as threatened under the ESA since 1997.
About a decade ago, the Idaho Department of Fish and Game began more-intensive monitoring of fish in tributaries that feed the Potlatch River, which, in turn, flows into the Clearwater.
What they found was astonishing, said biologists. The 400,000-acre Potlatch watershed, including Little Bear Creek's west fork, was far more important to the survival of the region's steelhead than many previously thought.
But the Dutch Flat Dam remained a stubborn bottleneck: According to a 2011 Fish and Game count, juvenile steelhead numbers below the dam were 100-fold those above the obsolete concrete barrier.
Fish and Game biologist Brett Bowersox said it's unclear if fish above the dam are progeny of steelhead that succeed in leaping it, or if they simply belong to a pre-dam population whose offspring just never bothered to swim to the ocean.
Either way, he said, it was clear this dam had to go if steelhead in significant numbers were to reach five miles of prime spawning habitat above the barrier.
"The dam is a significant impediment greatly reducing steelhead density above the dam," said Bowersox, who has pathetic photos of big steelhead adults gamely leaping from the creek, only to be rebuffed by the bulwark.
Enter the Latah County Soil and Water Conservation District, farmers, ranchers and others on the Palouse working on voluntary projects with landowners to save the region's natural resources and preserve agriculture.
The district won $500,000 from the Bonneville Power Administration and the federal Pacific Coastal Salmon Recovery Fund to demolish the structure and restore streamside habitat.
Starts and seeds from plants along the creek are being gathered to ensure re-vegetated areas include specimens from the site being restored. Now, final permits must be secured, including from the U.S Army Corps of Engineers, said Ken Stinson, the district's manager.
Whitney, Troy's mayor, hopes city employees who will oversee removal of the dam can begin by mid-August, given a timeline dictated by the seasons: Demolition must be completed by Oct. 31, when mountain rains begin in earnest.
Come next spring, he hopes steelhead swimming unimpeded into the creek's upper reaches will serve as a monument to a dam that's vanished.
"The people of Troy would like to see the fish run come back up through there," Whitney said. "That's pretty much what it's all about."