SPOKANE (AP) - Three federal agencies and the Kalispel Tribe have reached an agreement to spend $39.5 million over the next decade to improve stocks of native bull trout and westslope cutthroat trout in northern Idaho's Lake Pend Oreille watershed.

The money will be spent on a variety of projects intended to improve populations of trout species whose numbers have diminished since the 1950s, when the Albeni Falls Dam was built on the Pend Oreille River.

But the accord aims to do more than restore fish numbers and improve angling. Tribal officials point to the cultural significance tied to the fish and to rekindling the centuries-old fishing traditions used by their ancestors on Lake Pend Oreille, the Pend Oreille River and its tributaries.

"At some point in the future, we want our people to be able to harvest these fish again, and everyone else to be able to harvest them, too," Deane Osterman, executive director for the Kalispel Tribe's Natural Resources Department, said. "We want the improvements to benefit the entire community."

Bull trout are listed as a threatened species in Idaho and Washington, and westslope cutthroats are considered a species of concern. Fish biologists typically link health populations of both species with pristine, healthy watersheds.

Some older anglers can recall the days of reeling in trophy bull trout and cutthroat from the Pend Oreille system, according to Jim Fredericks, regional fisheries manager for the Idaho Department of Fish and Game. Lake Pend Oreille holds the world record for the largest bull trout: a 32-pounder caught in 1949.

Idaho officials cheer the idea of restoring the species in numbers that would enable anglers to keep a limited number. Rules now require anglers to put back both species, even though Lake Pend Oreille supports one of the West's healthiest remaining bull trout runs.

In 2008, the lake's bull trout population was estimated at 8,000 spawning adults. But that total is a fraction of its historic, pre-dam levels, when the bull trout had access to more than 200 miles of spawning streams, said Joan Jewett, spokeswoman for the U.S. Fish and Wildlife Service.

A central goal of the project is restoring fish passage over or around the 90-foot dam, Osterman said. The dam was built without fish ladders and prevents young gull trout from migrating upstream to Lake Pend Oreille, where the fish historically have matured into adulthood before swimming back downstream to spawn.

The dam also altered river flows, creating warmer pools of water. As part of the accord, the tribe and federal agencies will collaborate on dam operations, hoping to manage flows in a way that sends cooler water into the system for bull trout in late summer and fall.

Money also will be spent on acquiring and protecting habitat, researching the viability of building a hatchery and removing non-native, predatory fish from tributary spawning streams.

The three federal agencies involved in the accord include: the Bonneville Power Administration, U.S. Army Corps of Engineers and the Bureau of Reclamation.