Firefighters say it's unlikely that Wyoming's largest wildfire will be fully contained until fall or winter.
Rain and cooler temperatures are helping firefighters, but officials caution that the fire season is still young and warm, drier weather is returning this week.
State Forester Bill Crapser says dry lightning is in the forecast for Tuesday and Wednesday.
The nearly 150-square-mile Arapaho Fire burning northwest of Wheatland was 75 percent contained and firefighters were making good progress Monday afternoon.
But fire spokesman Jim Whittington said it's unlikely the fire can be completely contained because of a 2 to 3 mile stretch of very steep and rough terrain on the west side of the 10,272-foot Laramie Peak.
In western Wyoming, the 100-square-mile Fontenelle fire was 68 percent contained.