I saw a rolling ball of fire in the sky 500 ft off the deck traveling at 80-100 mph.

In the month of August 1979 I was overnight camping in Mammoth Lakes, California. I was located 100 ft north of highway 203 in the town of Mammoth Lakes. At approximately midnight to 0100 hr, I was looking at the stars when my attention was drawn to the sound of swirling fire. (It was similar to the sound when you swing an ignited long stick from the fire pit and swung slowly it in a circular motion). I looked to the east and saw a ball of fire rolling through the air at 500 ft off the deck. The ball was traveling at 80-100 mph from a direction from east to west and was approximately 50 ft in diameter. The object maintained its altitude neither accenting nor descending. The ball was red-orange in color very similar to a fire pit of burning wood. The ball also did not strike any hillside and I did not hear any impact after it left my view and hearing range.