Silvery dot makes two fast jumps before disappearing behind mountains.

While setting up a satellite dish on the ranch I grew up on, I looked up to see a silvery dot in the sky. 
I didn't think much of it as I watched, until it made an immediate ~15 degree jump south toward the mountains, stopped for a second or so, and then a further jump south past the mountain and out of sight. 
The sky was completely clear, the air was crisp and not at all foggy.  My father was nearby but not paying attention to the sky at all (and was very dismissive when I said what I had seen...I was 17 at the time).
Witness indicates that the date of the sighting event is approximate.  PD