When driving between Jordan, Montana and Circle, Montana on Highway 200 a bright blue ball of light completely circled the vehicle we were traveling in. The light was visible in front, behind, and on both sides and appeared to be a round ball of light that encapsulated the vehicle for one to two seconds and then disappeared. The driver of the vehicle and myself were shocked and could think of no cause or reason for the light and neither of us had ever seen this kind of bright blue light before. This is a remote area with no houses nearby and no light pollution of any kind. We stopped to look for a helicoper or airplane to explain the occurance and there was nothing visible in the sky. The night was completely clear with no moonlight and every star and the Milky Way shining bright.