Luminous, oval ring of light

In the summer of 1980 my 2 brothers and 6 of their friends came up to visit me and go camping on my property. They set up their camp near the river about 700' from my house. Early one evening at approximately 10 PM I went down to join my brothers and their friends at their camp site. We started drinking, just beer and having fun when someone looked up and said, "what is that?" I looked up and above us, at tree top level was a luminous, (white) oval shape like a huge smoke ring about 30'long and 15' wide, clear in the center. Around the perifery, inside and outside this ring were erratic pulsating flashes of white light. I remember what struck me the most was the shape of the flashing lights as they were triangular and seemed very unnatural also  how it remained perfectly stationary. There were no colors except for white and no sound. We all stared up mystifed and watched this light show display for 30 minutes or more, no one could take their eyes off of it. After a while I began to become concerned for everyones safety, not knowing what this was and I demanded we all go back to the house which we did in the darkness. Some of the guys said it followed us back up to the house but I didn't notice this. I would really like to know if anyone else has ever seen anything like this.
Witness indicates that the date of the incident is approximate.  PD