Dana, : 2 things , We did observe it for a long time, It didnt move a degree. And meanwhile over the almost 2 hour period the scatterd and then broken clouds slowly moved across the sky, passing this still object. It is roughly 2 miles above us and perhaps a mile or two horizontal to the east, not that far.
And 18,000 feet sounds like way up there but we are at 8,000 so not as high as might seem. My consulsoion is if this was a balloon it must have been tethered. Thanks for your suggetions, maybe we will find out sometime.