IDAHO

John Simpson concedes that he was "a bit naive" when, in 1997, he began clearing debris and beaver dams out of what he believed was an old side channel of the Salmon River on his central Idaho ranch. Bothered by the mosquito-infested swamps created by the dams, Simpson wanted to restore water flow that he says had been present since he bought the ranch in the mid-1980s.

The Army Corps of Engineers saw things differently. Later that same year, it determined that Simpson violated the Clean Water Act when he degraded an adjacent wetland while digging the channel. The Corps ordered him to fill in the channel, but Simpson refused, believing he had obtained verbal permission from the Idaho Department of Fish and Game. "I had never encountered a situation where cleaning up trash was bad," he says.

The Environmental Protection Agency is now taking Simpson to federal court. But last fall, the plot thickened when endangered chinook salmon spawned in the lower reaches of Simpson's illegal channel. With salmon fry darting to and fro, closing off the channel could constitute a taking of a listed species, and perhaps destroy what Idaho Fish and Game regional fisheries manager Mike Larkin believes to be "some pretty good habitat."

Environmentalists are sticking with the federal agencies: "The fact that private parties think they can go out and do what they want is the real issue," says Laird Lucas, senior council for the Land and Water Fund. Lucas thinks that allowing the channel to remain would set a bad precedent in the upper Salmon River Basin, an area already plagued with illegal stream diversions.

If the court orders the channel to be filled in, the National Marine Fisheries Service says it will work with the EPA to time the restoration so it would harm the fewest fish.