DENVER (AP) - Rising expenses and a shrinking budget are forcing Forest Service officials to consider closing hundreds of campgrounds, picnic areas and other recreation facilities.

By the end of 2007, each of 155 national forests and 20 grasslands must complete a recreation-site facility master plan evaluating recreation facilities on their condition, frequency of use and how they fit in the forest's recreation focus, or "niche."

Federal officials said they are weighing the value of each of roughly 15,000 campgrounds, trailheads with bathrooms and other developed recreation sites in the 193 million acres under the agency's authority against the costs of maintaining them.

The agency faces a $346 million backlog in maintenance and growing costs for fire suppression, which now makes up 42 percent of expenditures. Its budget for 2007 was cut 2.5 percent to $4.9 billion.

The Forest Service hopes to cut its maintenance backlog 20 percent by 2010, 70 percent by 2015 and 90 percent by 2020.

"We are looking at reality here," Jim Bedwell, the Forest Service's national director of recreation and heritage resources, told The Denver Post. "We're trying to best focus our funds as well as look at other ways to operate."

About 10 percent of facilities in 44 national forests that have completed their studies are targeted for decommission or closure, the Post reported on Sunday.

Sites could end up being closed or upgraded, said Steve Sherwood, director of recreation for the Forest Service's Rocky Mountain Region. Forest Service officials said volunteers, civic organizations and private groups perhaps could step in to run some facilities.

Decommissioned campgrounds will still be available for camping but won't have toilets, trash cans, picnic tables or water systems, Sherwood said.

The public will be able to comment on sites that are selected, and implementation could take five years, Forest Service officials said.

"Some of the sites being looked at have extremely low occupancy rates, in the 5 to 10 percent range," Sherwood said.

In the Grand Mesa, Uncompahgre and Gunnison national forests, 50 of the forests' 140 recreation amenities will have to close or be modified, said Lee Ann Loupe, a Forest Service spokeswoman.

The Arapaho-Roosevelt National Forest has enough money to operate 64 of its 177 recreation sites, with some others run by concessionaires, forest recreation staff officer Paul Cruz told The Denver Post.

Some other national forests and grasslands have yet to begin the master planning process or haven't announced what is planned.

One factor driving the review is the need to upgrade campground water systems to meet tougher federal drinking-water standards, officials said.

Most campgrounds were built in the 1960s and are out of date or falling apart, Bedwell said.

Scott Silver, director of the Oregon-based Wild Wilderness, said the Forest Service is placing too much emphasis on cost-cutting and outside groups' taking over facilities.

"It is a way to allow the government to get the job done without using tax dollars," Silver said. "When you starve government of the needed money, you force these other alternatives. You start to make government fail. Americans are becoming used to government failing."