Flying southbound, saw 2 silver spheres at 10,700'

We were flying southbound from Hood River, Oregon to Sunriver, Oregon. Sometime between 11:55am and 12:10pm at a cruising altitude (GPS) of ~10,500' my wife and I saw two metallic spheres. I was the pilot, and my wife was riding in the back seat of our cessna 182 with our toddler. I thought at first that I was seeing a bird, and remarked to my wife how weird it was that there was a bird up so high. She saw the object, and as we approached it we both realized it was not a bird at the same time. We both observed it to be two spheres, gray or metallic, connected by a horizontal tether. The spheres appeared to be about 12" diameter. They were perfect spheres. Our first thought was maybe party baloons, but they were too perfectly spherical and had no apparent surface deformations that would indicate a baloon's neck/tie-off spot. We did not observe a tether to the ground, or any means of propulsion. As we passed them, they appeared stationary to me but my wife said she thought they accelerated in the opposite direction of our track. We were on the CTAF frequency for the area, and heard no radio reports or disturbances. We were not on flight following, and therefore did not report to Seattle Center. I have a .kml file recorded from gps data on that flight.