1967 UFO somewhere between Utah and So. Calif. over highway finally reported!

My male cousin (I am female) and I were coming back to Southern Calif. from a Utah University when we saw a craft hovering over the highway in 1967.  It was one of the states in between but I can't be sure which and it was the early hours of the morning and dark.  The roundish craft saw us and silently darted behind a hill.  As I recall we went off the road to see it behind the hill.  It saw us again and this time shot behind a larger mountain and we could not follow it.  We never reported it because I was just a teen and thought it was probably a secret air force craft or something.  But now I am reporting it after the seeing Larry King show.  
I have a B.A. in Humanities from the Unv. of Washington and am now 58 years old.  My cousin is a year older and we were driving his beloved Camaro car.  Sorry can't remember much as a long time ago.
Witness indicates that the date of the event is approximate.  PD