The mission at Gettysburg National Military Park and Eisenhower National Historic Site (GNMP-ENHS) is to preserve the historic character of the parks to enable current and future generations to understand and interpret the events that took place at each park. Management objectives include maintaining the landscape as it existed during the historic 1863 Civil War battle (e.g., dense understory in woodlots) in GNMP and as it existed during Eisenhower's occupancy (e.g., patchwork of cropfields) in ENHS. Browsing by white-tailed deer (Odocoileus virginianus) diminished regeneration of native trees in woodlots and prevented crops from reaching maturity. Thus, to increase regeneration in woodlots and reduce crop damage, the National Park Service (NPS) began culling deer in 1995 to reach a density goal of 10 deer/km2 of forest. However, park managers were interested in an accurate population estimate to determine if their management goal has been met and possible methods to monitor future abundance.