Members of a U.S. Marine Corps color guard present

Members of a U.S. Marine Corps color guard present the colors during opening ceremonies for the 37th annual Marine Corps Marathon in Arlington, Va., Oct. 28, 2012. The event was established in 1976 and ranks as the fourth largest marathon in the nation. The race takes participants through Arlington and Washington, D.C., before concluding at the Marine Corps War Memorial near Arlington National Cemetery. (U.S. Marine Corps photo by Cpl. Tia Dufour)