First time I have heard of this controlled burn being done.

Gettysburg to burn battle sites this month

http://www.ydr.com/story/news/2017/04/03/gettysburg-burn-battle-sites-month/99974076/
Update, April 7

The National Park Service announced conditions are right to conduct a prescribed fire at Little Round Top on Monday, April 10, according to a news release.Roads are expected to reopen the following day, but Little Round Top will remain closed for safety reasons.If conditions remain favorable on Tuesday, Pardee Field, near the summit of Culps Hill, will also be burned, according to the news release.They plan to burn 52 acres on the west slope of Little Round Top and 14 acres at Pardee Field.

Fuel and weather conditions will determine the exact dates for the fires, according to a National Park Service news release.During the fire at Little Round Top several roads will be closed for portions of the day including Sykes Avenue, Warren Avenue, Crawford Avenue, South Confederate Avenue and Wright Avenue. Wheatfield Road also might be changed to one-way traffic for parts of the day as well.Little Round Top will have an area closed to pedestrians that could last two to three days, but people can watch the fire from a designated area on Ayres Avenue.
 
The park service's perform these fires to maintain the conditions of the battlefield as experienced by the soldiers who fought there. They also do this to preserve the open space of the landscape, maintain wildlife habitat, control invasive exotic species, reduce shrub and woody species and to reduce fire hazards, the release states.