HARRISBURG, Pa. (AP) Gov. Tom Corbett is following through on a budget-related proposal to expand natural-gas extraction below Pennsylvania's state forests and parks.

Corbett issued an executive order Friday that will allow drillers to bore horizontally into the rock deep below underneath public lands from adjacent, privately owned lands, so long as there is no long-term disturbance to the surface of the forests and parks.The governor's order also permits drilling from areas of forest that already were leased for gas drilling under previous administrations.Pennsylvania has 2.2 million acres of state forest land and 200,000 acres of state park land.Corbett has said he expects the order to generate $75 million for the state budget. He says future royalties from the new leases will be dedicated to expanding the forests and parks.It is unclear how area parks such as Hickory Run, Beltzville and Tuscarora will be affected.