Military Parks Pea Ridge National Military Park Pea Ridge National Military Park is a United States National Military Park located in northwest Arkansas near the Missouri border. The park protects the site of the Battle of Pea Ridge, fought March 7 and 8, 1862. Prairie Grove Battlefield State Park Authentic, expansive, and well preserved, Prairie Grove is known as one of America’s most intact Civil War battlefields. With more than 900 acres, this park commemorates the site of the Battle of Prairie Grove.