The massive Pine Creek fire this past summer (2012) that burned over 8000 acres and 5 homes, has officially been determined to be started by the spark from of an excavator. The excavator operator scratched a large rock while digging a hole, igniting a spark and lighting the quick moving fire.  A report from the US Forest Service says there was no criminal intent behind the fire, and that this type of construction work was legal during that time.  The excavator operator and the company he works for, has not been released.  The point of origin was north of Rocky Hollow Trail and about 700 feet east of the Yellowstone River and just south of Pine Creek.