Next Image Pioneer Fire 3 pm MDT August 5, 2016 The white line was the perimeter of the Pioneer Fire at 11 p.m. MDT on July 28. The red line was the perimeter at 7 p.m. MDT on August 4, 2016. The red dots north of the fire represent heat detected by a satellite at 3 p.m. MDT August 5, 2016.