PRINGLE, S.D. (AP) - Authorities say the Myrtle Fire near Pringle, which has scorched more than 16 square miles of land, .was likely caused by a road grader conducting maintenance in the Black Hills.
A forest service special agent determined the most probable cause of the fire was when the grader's metal blade fractured a rock on the road surface and ignited grass on the roadside.
The Myrtle Fire started on Thursday and was about 75 contained on Monday. It is expected to be fully contained by Wednesday.