Yellowstone lightsAs a tour guide, I took a group of people on a steam and stars tour. We went to fountain geyser did a tour then driving back to old faithful we stopped at biscuit basin and as we walked toasted Jewell gyser the mountain behind lite up like someone had driven a big pickup and it turned on its lights… It stayed on for about 5 minutes and went out. If you look at any satellite pic there is nothing man made that could have made that light