Graham Rahal, driver of the No. 15 National Guard Rahal Letterman Lanigan Racing car in the Verizon IndyCar Series, and NASCAR Sprint Cup Series driver Dale Earnhardt Jr. visited the Indiana National Guard training facility near Edinburgh, Ind., on July 23.

Firing a Howitzer and setting off explosives were among the activities that Rahal said "was very cool, very unique."

IMS photographer Chris Owens was along for the adventure and provided this gallery:
Graham Rahal and Dale Earnhardt, Jr.