On Wednesday, June 22, I was on a boat fishing trip with my father. We were on the North Fork of the Yuba River. On this day at about 5pm I took several pictures of the surrounding canyon and forrest. We returned home on Thursday June 23. While reviewing all the camping photos, I observed an object in the sky above the treeline in one of the pictures. I had taken three pictures within a few seconds of each other. The second picture has the object. The first and third picture of the same location have no object in them. The object looks rectangular, and shiny silver or white on one side. In the location where the photo was taken there were no aircraft in the sky and the only birds we had had seen were hawks or vultures. The area we were in is very secluded. There were no other people around, and no noise other than the river going over a rock bed.