Natural gas companies with rights to mineral and gas reserves below state and national parks could start drilling in otherwise protected areas, reports National Geographic in a series by Marianne Lavelle, who focuses on the impacts and problems of drilling in Pennsylvania. Sixty-seven companies already have stakes in the Marcellus shale geographic formation, a 389-million-year-old rock bed more than a mile beneath the Appalachian Mountains stretching from West Virginia to New York that likely holds large quantities of natural gas reserves. In many cases in Pennsylvania, mineral rights were separated from surface rights in the 19th century in deals that encouraged mining operations. As a result, the state has little ability to deny the mineral rights owners access to the mineral underground, though it will attempt to ensure that impact from extraction and drilling is limited. The state estimates that it owns mineral rights for just a fifth of the state's park areas. More than 2,480 permits for gas wells in Pennsylvania have been issued this year, and the industry expects more than 3,500 annually within a decade.

A total of 33 national park sites could be affected by the drilling, including 13 directly above the shale formation, among them a memorial to honor the passengers killed on United Airlines Flight 93 when it crashed on September 11, 2001, and the site of George Washington's first military campaign. Gas companies are already drilling on private lands adjacent to state forests, and the state does not own the mineral rights to about 15 percent of state forest lands -- additional areas for potential gas drilling.

The dispute has implications for larger issues for the federal government which, like Pennsylvania, does not own most mineral rights in parks and historic areas near the Marcellus shale formation. The government can only require gas companies to obtain approval and attain bonds to pay for reclamation if the company must cross federally-owned land or water to get to the drill site. If not, the regulations may not apply. ProPublica has also reported on the conflict between government agencies and gas companies in Pennsylvania, reporting in early October about the poor quality of drinking water that resulted from the drilling.