A fire burning Monday afternoon reached across 400 acres of Mark Twain National Forest.

Firefighters there said it may be later this week before they get it under control, the Associated Press reports.

U.S. Forest Service officials in south-central Missouri have been battling fires in the park since last year. The drought has stretched the normal fire season by months, continuing into the summer. Forest Service firefighters have seen many more fires than usual this year started by “dry lightning,” which occurs without rain and has struck four times this year.

The fire, fueled by large amounts of wood and debris left in the area from a 2010 tornado, is proving difficult to extinguish in the hot, dry weather. The steep terrain of the area also is obstructing firefighters’ efforts.

National Forest officials say some private lands may be affected by the fire, but canoeing on the North Fork River has not been interrupted.

| Ian Cummings, icummings@kcstar.com