Orb sighting

In the spring of 2000, My girlfriend and I were on a trip from Seattle to Montana.
On the way, we decided to visit a friend. That turned into about a 5 hour detour into the Olympic Mountain area. It turned out that when we got there, no one was home. We later found out our friend had gone to the hospital that particular night.
Anyways, using a map, I decided to take a two lane highway that would merge back to I-90 in the Spokane area. It was a long, grueling drive and finally, I had to pull over from fatigue. I was in a heavily wooded area and it was pitch black. After dozing for some time, there was a sudden thud by the rear left quarter panel that woke me and shook the vehicle. In one motion, I opened my eyes, turned the key and floored it. I have no idea what hit the car. Within a half hour, I was again heavy eyed. I pulled over again. This time, close to Spokane, I could see the AFB's Tarmac and was approximately 1/4 mile outside the cyclone-fenced area. It was still dark, I think around 4:30 AM and the distant lights from the perimeter buildings and outside lighting made me feel a little more at ease.
Suddenly, by the corner of a hanger type building on the far edge of the tarmack I saw a huge orb shaped light, about 6-8 feet in diameter. There were 4 or so persons standing there in military green. The orb slowly rose bertically into the air without noise, and at 80-100 feet, then moved in my direction. I shook my girlfriend awake as it moved outside the fence and directly above the car with no sound what-so-ever. Once again, I turned the key and floored it. I didn't look back and didn't stop again until we were out of Washington. After the "bump in the night" this freaked me out. I have my girlfriend as a witness and am wondering if anyone may have an idea what that orb was.