PORTLAND, Ore. — An environmental group filed a lawsuit Tuesday that it hopes will force the U.S. Forest Service to stop routinely fighting wildfire.

Forest Service Employees for Environmental Ethics, based in Eugene, filed the lawsuit in U.S. District Court in Missoula seeking a court order to force the Forest Service to prepare an environmental impact statement on wildland firefighting that includes an examination of the toll in human life.

‘‘The thesis of our case is that fighting fires is what has gotten us into the trouble we're in,'' said Andy Stahl, executive director of the group. ‘‘It's time to end the war against fire and learn to live with fire and manage it, rather than fight it.''

Because an environmental impact statement must examine social impacts, it would have to consider the deaths of hundreds of firefighters killed fighting wildfires in the past century, including 26 this year, said Stahl.

The lawsuit focuses specifically on Forest Service use of fire retardant, claiming the agency has violated the National Environmental Policy Act by failing to go through an open public process to examine the environmental impacts of dropping retardant on wildfires.

It argues the Forest Service violated the Endangered Species Act by failing to consult with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service on the lethal effects on threatened and endangered bull trout and salmon of dropping fire retardant in streams.

Joe Walsh, a Forest Service spokesman in Washington, D.C., and Paula Nelson, a spokeswoman for the Forest Service's Northern Rockies Region, said they had not seen the lawsuit and could not comment on it. They also declined to comment on the agency's current use of fire retardant.

Stahl said FSEEE had copies of e-mails and letters referring to an internal environmental assessment the Forest Service has used to justify its use of fire retardant, but the National Environmental Policy Act requires a public process, which has never occurred.

The lawsuit includes an affidavit from Ken Weaver of Yakima, Wash., whose only son, Devin, was among the four firefighters killed July 10, 2001, fighting the 30-Mile Fire in Washington.

‘‘It's one thing to die in the service of your country for a justifiable proper cause,'' said Weaver. ‘‘The problem is we've got these kids out there dying for something that is scientifically bankrupt. We are subverting nature, causing more damage than good, and we are taking kids' lives. That is just so wrong.

‘‘I'm not the only one to have ever suffered this kind of loss. But when you lose something more valuable than anything you ever dreamt having, it just shakes you down to the bone marrow.''

The lawsuit argues that wildfire is a natural phenomenon in forests throughout North America, but the Forest Service policy of trying to put out nearly all wildfires over the past century has created conditions that have produced huge wildfires in recent years.

In 2002, wildfires burned 6.9 million acres at a cost of $1.6 billion dollars, according to the National Interagency Fire Center. That exceeded the 10-year average of 4.2 million acres. Wildfires this year burned 3.2 million acres.

As part of the battle against wildfire, the Forest Service uses an average of 15 million gallons of fire retardant each year, and some years as much as 40 million gallons, the lawsuit said.

The fire retardant used by the Forest Service contains sodium ferrocyanide, which breaks down to form hydrogen cyanide, which kills fish, when it is mixed with water and exposed to sunlight, the lawsuit said.

The lawsuit maintains that fire retardant drops have been responsible for numerous fish kills, including one on the Mancos River in southwest Colorado in July 2000.