Blue flashing light (Basket ball) sized. Fast Mover.I was traveling north on hwy 97 approximately 5-6 mile north of Madras, Oregon 4:30 AM. In the distance I could see a blue flashing light in the road ahead. It appeared to be about a half a mile (I guess) ahead of me and not moving. The weather was high overcast and dry. My first reaction was, it was a police car. I began to slow down and as I approached, the light began to move away from me at a speed about double of my speed. I was moving about 65 mph. It was moving so fast I was trying to figure out how it could be a car. The light still flashing at the same rate turned +/- 90 degrees and moved west into a very large irrigated field. My guess it was 5 -10 feet off the ground and did not move up or down. It looked to be about the size of a basketball. Again it was dark and I did not have any references to compare it to. It traveled out what appeared to be about a 1/8 - 1/4 mile and turned south now going the opposite direction I was moving. I followed it visually the best I could. After it passed my sideways field of view I began to watch it in my mirror. It went past me a little further (hard to tell how far in the dark and I was still moving fairly fast). It looked like it turned 90 degrees again and came back to the road. The light looked as thought it came up behind me and I lost sight of it. I did not see any residual light flashing around my vehicle. Again it happened very fast (30 seconds +/-) and I was watching the road at the same time this was all going on. I was driving a 2005 Ford pickup. The exterior mirrors are large and it also has an interior mirror.