The U.S. Forest Service started a fire in the ponderosa pines southwest of Amidon on Wednesday for the first time in its management history.

The 70-acre fire was relatively small and burned out an area near where a wildfire sparked by farm equipment swept through 4,000 acres of prairie grass and pines in the Deep Creek drainage in September 2005.

The acres are on the Medora district of the Little Missouri National Grasslands.

District supervisor Ron Jablonski said the prescribed burn was a success because it appeared the fire successfully burned out small ladder trees and downed trees that make up the fuel load in a wild, unplanned fire.

The agency has been planning the prescribed burn for several years and switched from a fall burn schedule to a spring burn because the past several fall seasons have been too dry and hot. This one was aided by spring snows and last weekend's rainfall and forest conditions were not tinder dry, though Jablonski said it was still hot enough to ignite big downed trees.

He said the Forest Service will go back next spring and the one after, if conditions are right, to burn another 230 acres in the pine forest.

He called Wednesday's fire a success because it was efficient, effective and safe.

The burn area will be surveyed by fire specialists to see if it met the goal of burning out at least 60 percent of the under story ladder trees and downed trees.

Typically, fall burns are preferred because they can be backed up against a snow forecast as management insurance.

Spring fires are considered a higher risk and the window of opportunity for the perfect conditions is generally fairly narrow, Jablonski said.

Fire crews went back out Thursday at dawn and found that "everything held" during the overnight, he said.

The 2005 wildfire burned through some 2,000 ponderosa pine acres, most on private land owned by Loren Jacobson and some on the Robert Hanson family Logging Camp Ranch.

The small far southwestern reach of North Dakota is the only habitat that can sustain the ponderosa pine species.