F.E. WARREN AIR FORCE BASE, Wyo. -- The 90th Security Forces Group on F.E. Warren Air Force Base held the 23rd annual Crow Creek Challenge Sept. 22, 2017. The Crow Creek Challenge is an event that put the mental and physical capabilities of the 90th Missile Wing’s defenders to the test with various tasks such as a 2.2 mile ruck march, an obstacle course, an active shooter scenario and other events.