ALBUQUERQUE, N.M. – As firefighters battle blazes in New Mexico and Colorado that have forced evacuations and destroyed hundreds of structures, the U.S. Forest Service chief is renewing his call to restore forests to a more natural state, where fire was a part of the landscape.

Experts say a combination of decades of vigorous fire suppression and the waning of the timber industry over environmental concerns has left many forests a tangled, overgrown mess, subject to the kind of super-fires that are now regularly consuming hundreds of homes and millions of acres.

The Forest Service is on a mission to set the clock back to zero and the urgency couldn’t be greater, Tom Tidwell said. The plan calls for accelerating restoration programs – including prescribed fire and mechanical thinning – by 20 percent each year in key areas that are facing the greatest danger of a catastrophic fire.

This year’s target: 4 million acres. The budget: About $1 billion.

“We need to understand the conditions we’re facing today,” Tidwell said. “They’re different than what we used to deal with. We’re seeing erratic fire behavior, more erratic weather.”

In southern New Mexico, a lightning-sparked fire raced across more than 37,000 acres in recent days, damaging or destroying at least 224 homes and other structures in the mountains outside of the resort community of Ruidoso.

The Colorado blaze, about 15 miles west of Fort Collins, was still spreading. It had burned 78 square miles by Thursday, destroyed more than 100 structures, including at least 31 homes, and forced hundreds of people from their homes.

The accelerated forest restoration effort is focused on several landscape-scale projects, the largest of which is a 20-year plan that calls for restoring 2.4 million acres across four forests in northern Arizona.

The Forest Service recently awarded a contract to start thinning the first 300,000 acres.