Zombies! Run!
Runners exit the north portal of Cheyenne Mountain Air Force Station, Colorado, during the Zombie Tunnel 5k Fun Run, Oct. 20, 2017. The run gave participants the opportunity to run the full length of the Cheyenne Mountain AFS tunnel. (U.S. Air Force photo by Steve Kotecki)

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Photo by: Steve Kotecki |  VIRIN: 171020-F-JL266-1222.JPG