I live in the mountains of Central Idaho. This morning, 3/19/10, at approximately 11:20, five F-15 Eagle fighters flew over our place (located in a narrow mountain canyon/valley)from south to north. Fighter aircraft are not unusual here, as training flights from Mountain Home A.F.B. are all too frequent. What was unusual was both the number of planes and the flight pattern. Normal flight training flight patterns here are east to west or vice-versa, and generally consist of two planes. This morning, they flew from the south to the north, and there were five aircraft rather than two.At approximately 1300 hours, I heard the fighters again and went outside to look. There were none in view, but the sound of the engines was clearly audible. As I scanned the sky (partly cloudy, surface wind from the west at about 10 m.p.h., temperature 44 degrees) looking north, I noticed something unusual hovering above top of the slope. The approximate distance to the object would have been 300 yards. The object was shaped like a previous year, dead "Tumble Mustard" plant, with multiple "branch-like" protrusions from a central stem pointing upward at approximately 45 Degrees. The difference was that this object was effectively white rather than brown, almost to the point of being translucent, nor was there any frost remaining on any plants in the area after 9:00 this morning. Further, the object appeared to be between 15-20 feet high and hovering in place about 30 feet above the ground, rather than being pushed to the east by the winds. Tumble mustard is 3 feet tall at maturity. This was not a flying weed.The object began to slowly ascend to the west, then southwest until its position had shifted from the original spot of observation by approximately 90 degrees. This movement took about 30 seconds. It then ascended at a rapid pace virtually straight up, slightly to the west, and disappeared from view after about three seconds. All of this movement was both into the wind and clearly exhibited the gaining of altitude.Upon first sighting the object, I thought probably the same thing anyone else would have. "What the hell is that?" I am about as outdoorsy a person as you can get - hunting, fishing, hiking, gardening, as well as my entire work-life being spent outdoors. I have seen many things blown into the sky by winds, but nothing like this and nothing of such a shape that went against the direction of the wind gaining in elevation the entire time, none the less disappearing from view in mere seconds. Truthfully, I'm not very pleased with the whole event and for approximately 15 minutes immediately afterwards, I was just a bit rattled. I cannot logically explain what I saw.