On or about May 26.The somewhat smooth cloud ceiling was at approximately 3000 feet. There were patches of clear sky as well. Two days prior I had heard the chatter of returning flocks of cranes and it was happening again, so I stopped my yard work and took the time to watch them enjoy the thermal lift provided by rising heat from Spruce Grove. I have been doing this for several years. The birds have a distinctive sound that is easily recognizable. Later, I looked up the height at which the birds fly. It's approximately 2400 feet, so I am assuming that is at or near the altitude of the flock. My view of them was framed by the second story edge of my home to the east and a tree in my neighbor's yard to the west. I stepped back into the shadow of my home to get a better view of the birds as watched. As I watched, above the birds, who were not disturbed, there came a circular cloud from the west. It was large and moving south by south west at, my guess, forty to sixty miles per hour . If you have ever watched a blunt nosed ferry ship plow its way through the ocean then you can imagine how this thing was moving through the sky. It seemed to be producing the fog/cloud around itself in an apparent but poor attempt to disguise itself. At about halfway across my field of view it changed direction to south. There was no curve to the turn, nor did the cloud/craft bank for the adjustment. It seemed to be emitting a shimmering cloudiness around itself, but nevertheless it was blatantly obvious is was controlled and was not a cloud. Every now and then a glimpse of something light grey could be seen. After a few seconds it tilted upward about twenty degrees and began to climb. It was at this point that I ran into the house to find my camera and take a picture. When I returned, it was gone. As for its size, I can best describe it as being about the size of the bottom of a standard coffee mug held at arm's length over my head. Needless to say I am spending a lot of my time looking up.Ex RCAF