I was driving to my parent���s house in the foothills of the Bighorns about fifteen miles south of Sheridan, Wyoming on the way to Story, Wyoming at around 9:30PM Sunday, Novemeber 16th 2008, when, about midway on my drive, I saw a large and stable light in the sky. Its color was neutral and did not have visible wing-tip or tail strobes. As I observed the light over the course of several minutes, it became apparent that it was stationary (or nearly stationary, perhaps descending slightly) and that I was quickly approaching its position. The rate of my approach indicated that the light was low and near. These observations all ruled out most forms of airplane. The craft had to be VTOL and relatively small.About eleven miles out of town there is a ���tank farm��� ��� a filling station for fuel trucks. This is at the junction of Mead Creek road and Highway 87. I found the light to be centered directly above the tank farm and very low. I did not rule out the possibility it could be a helicopter and I wondered whether the tank farm could have a helipad to receive some sort of business by helicopter.I slowed to approximately 30-40mph, muted my stereo and rolled down the window to listen for the beats of a helicopter blade. I could hear no blade nor any sort of engine roar. Simultaneous traffic on the highway, consisting of two cars within the half-mile behind me, did not seem to slow to observe the light, but I obviously could not see what was going on inside them.Depending on the size of the object, it seemed to be, judging by my position and the stature of the gasoline tanks, only about 100-200 feet off the ground. Clearly, this is only explicable if the craft were a small helicopter and was coming in for a landing on site.At the time, I continued driving. By the time I reached Bird Farm road, about another mile down Highway 87, my inner Fox Mulder had clearly won and I whipped the car around and sped back to try and get a definite confirmation that the craft was a helicopter by either watching it land or listening (at a complete stop) for the sound of blade clips.I reached the location in less than a minute and passed it twice. No traffic was around, so I passed it both times at 10mph, radio off and windows down. There was no trace of the light or any craft anywhere in the sky or on the ground. There was no visible helicopter at the site and absolutely nothing was in the air. The cloud ceiling was very high and could not have concealed a helicopter that had just taken off. Similarly, no stars were visible to camouflage the craft if it had taken off and achieved a very high altitude somehow in that short period of time.When I passed the tank farm the next morning (11/17/08) on the way to work, I observed that there is no place on the site that I could see designed for a small helicopter to land. The physical description of the light is difficult. No features were distinguishable. If there were multiple lights on the craft, they bled into one, singular neutral-colored upside-down teardrop shape (which may have been due to refraction and not indicative of the shape of the actual craft). I could not distinguish wings or a tail. No blades or propellers were visible or audible. It did not exhibit any lateral movement. It seemed to have descended as I neared the position, but this movement was very subtle and smooth. It was definitely only a few hundred feet off the ground at most when I passed it, though I am pretty sure it was much higher than that at the moment I first spotted it.I had noted the time when I left town and again during and after the sighting. There was no ���missing time.��� The entire sighting lasted only a matter of minutes. I had also seen something similar in a nearby location when I was in high school, but later wrote it off as a (strangely low) helicopter. Several ranchers in the area may have private helicopters, but the absolute noiselessness of the craft, its lack of tail or strobes, and the speed of its disappearance make that solution difficult.