Fort Sill, OK

ZIP code 73503 covers Fort Sill, an active U.S. Army installation northwest of Lawton, Oklahoma. Its notable landmarks include Medicine Bluff, the Old Post Quadrangle, Fort Sill National Historic Landmark and Museum, and the U.S. Army Field Artillery Museum. Fort Sill National Cemetery is also located there; it includes the grave of Apache leader Geronimo. The area combines historic sites with military training and support facilities.