We were camping at great basin national park about 7500 ft.Elevation .After sunset looking north we noticed an area in the flat basin where we saw some lights.After watching a short while we could see orbs slowly dropping down and entering something from one side and leaving from the other side.This was located 5 miles of so from the campsite.We could see 4 to 5 orbs come to that area at a time.One at a time they would drop and appear to enter.Not very long after first observations we noticed a couple orbs coming closer to the campground.As far as i know they did not come any closer than a half mile from our camp.They just stayed close to the top ridge of the mountain. the one on the right would sometimes go on the other side of the ridge and not be seen,but would return again a couple times during this period of time.About an hour of watching i witnessed the one slowly move back and drop down to what by this time i am thinking it to be a mother ship. i watched the activity for several hours until i went to sleep. the next morning i drove toward the area,but all i found was flat land and not much road access. i would guess there was 50 to 100 orbs.