We saw a very bright light, hovering, and then moving rapidly away over the desert hills of SE Washington.Traveling from Tri-Cities to Walla Walla, coming over Nine Mile Hill, I noticed a very bright light ahead of us and to the south, over the desert. It looked like a plane, but for the lights to be that bright we would have had to be within 100 yards of it. The light appeared to be a couple of miles away. We went behind a hill for about a half mile & when we could see to the south again it was still there. Using the lights from the windmills on the hills (approx. one mile to our south) to position it, it appeared to be stationary. We continued to travel east, and after about a minute, the one large very bright light changed to two smaller lights. When that happened we could make out the shape a little better. It seemed to be oblong & shone silver in the reflection of its lights. There almost seemed to be a long skinny pipe coming out of the bottom at an angle. It was too far away to estimate size. We drove for about another mile and at the bottom of the hill, when the object was directly to our right, there was a road heading straight towards it. The object appeared to stay stationary this whole time. We turned right and slowed to a stop, about 20-30 yards down the road. However, as soon as our headlights swung around to point in the direction of the object, the two lights went out. Within a few seconds a small red light and a small blue light appeared and began blinking like a normal airplane would. The lights then moved off west-northwest (not towards the airport in Tri-Cities) very, very rapidly. Faster than a small plane like a Cessna could travel. We didn't hear any noise during any of this time.