DILLON (AP) -- A fire likely sparked by lightning in the Beaverhead-Deerlodge National Forest southwest of Ennis grew Sunday to 100 acres.
The Johnny Ridge fire started on Saturday, and was fanned by steady winds of 30 mph that night which produced spot fires up to one-half mile ahead of the main blaze, forest spokeswoman Jack De Golia said.
Forest firefighters reported cooler temperatures and a heavy frost Sunday morning. Three engines and a helicopter also are working to contain the blaze, which has burned less than one square mile.
''We have a good opportunity to catch the fire today,'' Ennis district ranger Mark Petroni said.
The fire is burning trees and grass above 8,500 feet in the Gravelly Range. No buildings were threatened and no one had been injured, but areas around the fire were temporarily closed for public safety reasons, De Golia said.
