Smoke still rises from smoldering stumps in north-central Washington, months after a wildfire roared through 274 square miles of state and federal land.

To protect the hundreds of miles of scorched roads, trails, river channels and wildlife habitat from erosion, the U.S. Forest Service hopes to spend $28 million over the next two years to complete what may be the most expensive rehabilitation project it has ever undertaken.

"The flames have died down, and the firefighters have gone home, but the work is just beginning," said Doug Jenkins, a Forest Service spokesman.

The large fire — the result of two fires joining after being sparked separately by lightning in July — burned 175,184 acres just south of the Canadian border, briefly threatening the hamlets of Conconully and Loomis, tucked away in the thick Okanogan and Wenatchee national forests.

The forests, devastated by a bark beetle outbreak, provided ready fuel. In some areas, all the ground cover or duff — small or downed trees and branches, bushes and shrubs — burned away. Standing trees are but scorched sticks, their root systems beyond repair. Soil has been seared to a fine, gray ash. Twenty-three percent of the fire zone burned severely.

The recovery effort doesn't try to replace what's been damaged by the fire, but to reduce further harm to now-fragile land that is exposed to the elements. The team — composed of engineers, botanists, biologists and cultural resources specialists, among others — evaluates hazards and develop a recovery plan.

The Forest Service already received $14 million to begin the work this fall before heavy snow falls, and hopes the rest of the money will be approved next year to complete the project.

Work includes clearing downed trees and cutting hazard trees that have been weakened and could fall on 259 miles of road and 70 miles of trail inside the fire lines. Culverts must be rebuilt, and in some cases enlarged, to handle runoff from snow and rain in the coming months.

Erosion poses the biggest risk, resulting in landslides and sediment loading in streams important to threatened and endangered fish, said Mel Bennett, a forest hydrologist assigned to the recovery team.

An estimated 270 truckloads of straw have been delivered to the fire area alone. It will be dropped by helicopter in 1-ton bales over the heaviest burn areas. The straw provides cover from rain and snow for scorched soil.

Less severely burned areas are to be fertilized to help damaged plants recover. Roughly 7,000 acres are to be seeded with sturdy grasses, and workers will clear such noxious weeds as diffuse knapweed and Dalmatian toadflax that could choke out emerging plants.

Terry Lillybridge, a plant ecologist on the team, estimates a 50-50 chance of success.

"The success of seeding depends on what happens next spring," he said. "You end up with a rainstorm that might not normally be a problem on a vegetated slope, become a problem. Maybe in a case where 80 percent of the rainfall might soak in, maybe 80 percent comes downstream instead."

For Jenkins, Bennett and Lillybridge, the operation is the largest they can remember after many years with the Forest Service.

"It's the biggest I've been associated with in my recent memory — at least in the last 30 years," Bennett said.

The most expensive post-fire rehabilitation effort came after a blaze in Colorado's Pike-San Isabel National Forest, which consumed 133 homes en route to scorching 215 square miles in 2002, said forest spokeswoman Cass Cairns. The recovery cost was $18.1 million.

The Washington fire won't be contained until the area sees three days of rain equaling a half-inch or 5 inches of snow.