silver object seen on backpacking trip near Mt. Whitney, CA - 1993

My son, nephew and I were backpacking on the trail that leads up to the series of cottonwood lakes just south of Mt. Whitney, CA.  While hiking on the trail we glanced across the canyon to the opposite ridge line and there was a silver colored round object just hovering above the ridge.  It darted in short bursts in several different directions while we watched it.  It was definately NOT an aircraft I had ever seen before.  It would hover motionless for a few seconds and then burst to the left, hover, then burst to the right, hover, then burst upwards, etc.  Each time it hovered it would sit for a few seconds and then burst.  This went on for several minutes and finally dropped behind the ridgeline of the opposite canyon wall.  It was never seen again after that.
 That night I saw something completely different.  That will be in a separate post.
Date is approximate.  PD