POCATELLO, Idaho (AP) _ Four men pleaded innocent Thursday to charges filed in connection with a fire last summer that charred 120,000 acres in the Targhee National Forest and Yellowstone National Park.

Roy Momerak, Herbert V. Butler, Nathan Wright and Leland J. Owens, all of Blackfoot in southeastern Idaho, entered their pleas before U.S. Magistrate Craig Jorgensen. No trial date was set and all four were released on their own recognizance.

U.S. Attorney Maurice Ellsworth filed a notice of violation against the men last month in Boise following a lengthy investigation into the fire, which began in Idaho, about one-quarter mile west of the Yellowstone Park.

Targhee Administrator Chick Sorenson said the investigation concluded the massive blaze was started by woodcutters with a lighted cigarette on July 22.

Ellworth said last month the four were not charged specifically with starting the North Fork fire, although federal prosecutors would try to link their actions and the end result in court.

The men were charged with violating regulations for federal lands for allegedly discarding burning material and for improperly disposing garbage.

The fire threatened the Old Faithful area, Canyon Village and the town of West Yellowstone, Mont., before it was finally contained in September.

If convicted, the men face a maximum $500 fine and six months in jail.