BILLINGS (AP) -- A lighting-caused fire had burned 5,000 acres on the Crow Indian Reservation by Monday night, authorities said.
Another lightning-caused fire started Monday on the Charles M. Russell National Wildlife Refuge north of Winnett, while a third fire was close to being mopped up near Ennis.
The Big Horn Fire on the Crow Reservation was reported about 2:30 p.m. Saturday in a wooded canyon about 20 miles southwest of Fort Smith. By Monday night, the fire had spread throughout a 5,000-acre area of dry timber and tall grasses.
''With the continued warm temperatures and the abundance of dry fuel, we're getting into fire season,'' Larry Elder, intelligence coordinator for the Billings Dispatch Center, said Monday night.
A specialized team is expected to take over managing the fire Tuesday morning. Pat McKelvey, a fire information officer with the Northern Rockies Incident Management Team, said as many as 200 firefighters would be involved in the battle within the next day or so.
Two single-engine airplanes, four fire engines, a water tender, a grader and two bulldozers were among the equipment already on the reservation. Authorities also requested at least two helicopters.
Aircraft will be drawing water from Bighorn Reservoir.
No injuries were reported Monday night and officials said evacuations would be unlikely. No structures were threatened.
The McArthur Fire was reported Monday afternoon in the Charles M. Russell National Wildlife Refuge.
A pilot reported the fire in Fisher Coulee, in a spot where lightning struck a tree on Sunday, said fire management officer Mike Granger.
''We've dropped quite a bit of retardant on it,'' Granger said.
He said the fire had burned about 5 acres when crews first arrived, but blew up to 250 acres within 90 minutes.
''It was spotting and being pushed by the wind,'' he said.
Granger said crews planned to burn out areas around the fire and ''hopefully get rid of most of the fuel within the perimeter of the fire,'' before strong winds forecast for Tuesday arrive.
Granger said two crews, a helicopter and seven engines were fighting the fire.
And southwest of Ennis, cooler temperatures and a letup in strong winds were helping firefighters as they mopped up the 125-acre Johnny Ridge Fire.
The fire in the Beaverhead-Deerlodge National Forest was apparently sparked by a lightning strike on Saturday. Winds of 30 mph fanned the flames and the fire had burned just over 100 acres by late Sunday.
The wind also led to hundreds of spot fires over another 400 acres ahead of the main fire, and crews were mopping up those hot spots on Monday as the winds tapered off.
''If we don't have any wind again, we could see this thing wrap up pretty quickly,'' he said.
The fire was 85 percent contained Monday evening, said Forest Service spokesman Jack de Golia.
De Golia said the fire was a bit unusual in that ground vegetation was green and wet enough that it didn't burn readily. But the fire got into the upper branches of trees, creating a crown fire that spread through the treetops, often leaving the ground vegetation untouched.
About 130 firefighters were battling the blaze, along with three fire engines and a helicopter.
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.