As wildfires across the nation continue to get bigger and burn longer, the agency has been forced to spend a larger portion of its overall discretionary budget to pay for firefighters, helicopters and air crews. Five former Forest Service chiefs recently told Congress those soaring costs are affecting everything from campground maintenance to research on national forest lands. "As Chiefs of the U.S. Forest Service from 1979 to 2007, we wish to express in the strongest way that the Forest Service has been put into an untenable financial situation due to the way fire suppression funding is being handled in the federal budget," their statement said. The statement was signed by R. Max Peterson, F. Dale Robertson, Jack Ward Thomas, Michael Dombeck and Dale Bosworth. At one time, the Forest Service depended on the funds it took in from its timber sale program to keep its checkbook in the black. Whenever fire suppression costs soared past appropriated levels, the agency simply borrowed money from the trust funds deposited by timber sale purchasers. When the fire season ended, Congress generally reimbursed those funds through supplemental appropriations. In the 1990s, the agency's timber sale program was slashed by 80 percent due to environmental concerns and those trust funds nearly dried up. Congress now requires the Forest Service to base its fire suppression funding request on a 10-year average of firefighting costs. A decade of drought, insect infestations, rising temperatures and a growing number of homes being built in the wildland-urban interface has resulted in bigger and longer-lasting fires that are more expensive to fight. As a result, a growing proportion of the agency's total budget is being used to fight fire. In 1991, the Forest Service spent 13 percent of its total budget on wildland fire management. Last year, 45 percent of the agency's budget went to fighting fire. In the Northern Region forests of Montana and northern Idaho , budgets for everything from recreation to private forestry are getting squeezed. For instance, in fiscal year 2005, the region had $43 million to spend on maintenance and construction. Two years later, that budget had dropped to $28 million. Mike Paterni, the Northern Region budget officer, said there are several reasons for fluctuating budgets, including other priorities in different regions and the total funding package allowed by Congress. If the costs of fire suppression continue to rise under this current funding scenario, Paterni said the agency will face difficulties in funding other programs. "Fire suppression costs is the most significant overarching issue for the Forest Service right now," said Don Black, the Northern Region's assistant director of fire program planning and budget. "We're really looking hard at ways to be cost effective - but you can never fight fire on the cheap. This will never be an inexpensive business." Costs for everything from a gallon of gasoline to a bag lunch continue to increase every year, Black said. At the same time, society requires the agency to attempt to protect a values that range from wildlife habitat to physical structures, he said. "Twenty years ago, the wildland-urban interface challenges were generally found in California ," Black said. "Anymore it's right here in Montana , Wyoming and Colorado . It's very unusual any more to have a wildfire without having some roofs on the skyline that will be in harm's way if someone doesn't stop the fire sooner." While there's some debate over whose responsibility it is to protect those homes, the Forest Service typically picks up the lion's share of fire suppression costs, he said. Retired Forest Service Chief Dale Bosworth of Missoula said society expects the agency to step in during these national emergencies. Congress shouldn't ask the agency to dig deep into its other accounts to pay the bills, he said. "It would be like Congress telling FEMA after a major hurricane to suck it up and pay for it out of its annual budget," Bosworth said. "It's crazy. These are national emergencies. The Forest Service is asked by the national public to step up and put the fires out." The Forest Service's budget should include appropriated monies to hire firefighters and train them, Bosworth said. Additional funds should be set aside to pay for initial attack on fires, he said. But once a fire escapes those first efforts and grows large and expensive, Bosworth said, those costs should be paid from a separate emergency firefighting fund. "Of course, there would have to be efforts to ensure the Forest Service remained cost effective," he said. "There can't be an open checkbook." If Congress fails to act, people who depend on national forest lands for recreation or their livelihoods will feel the agency's funding woes. "I think people are seeing it already in the way campgrounds are no longer being maintained like they used to be or trails not being taken care of like they once were," Bosworth said. "People get irritated with the Forest Service. What they don't understand is the agency is limited in what it can accomplish when it's spending all of its money on firefighting." The 10-year average firefighting cost for fiscal year 2008 was $911 million - a 23 percent increase from just last year. The Forest Service projects the costs could exceed $1 billion by 2009. "If you look down the line three, five, 10 years from now, firefighting costs could presumably be close to 100 percent," Bosworth said. "Congress shouldn't allow it to get that bad. Congress needs to look at this issue in an objective way before it becomes a crisis."