I was ~13 years old in The Civil Ait Patrol, this occurred in Truckee, Ca at the Truckee Airport.
We were doing standard marching exercises and our troop leader was a former SR-71 mechanic/maint person...
It was a full moon - and as our gatherings typically started after 5PM - it got dark fairly quickly.
We were marching and then looking to the mountain line in the horizon, we saw a light come up over the mountain line and fly vertically up at a steady clip as it was near the moon which had also just risen over the ridge.
We all watched, speculating what type of plane this was (Civil Air Patrol was like the cub scouts for the air force)
As we watched and guessed, this craft flew straight up from the mountain - then directly toward us.
I came to a complete hover just above us by about 300 feet. The craft was the classic triangular shape with large round whit lights at each corner.
As it hovered - the troop leader said "OK KIDS - EVERYONE INSIDE NOW!!!" and he ushered us into the end of the hangar building that had our CAP office.
Ever since then.... I've had an interesting relationship with believing UFOs...