Enerplus Corporation, together with subsidiaries, engages in the exploration and development of crude oil and natural gas in the United States and Canada. The company holds a portfolio of approximately 177,000 net acres comprising 33,000 net acres in the Montney formation; 73,000 net acres in the Duvernay formation; and 71,000 net acres in the Stacked Mannville. Its property portfolio also include 69,000 net acres located primarily in Dunn and McKenzie counties in North Dakota; and approximately 52,000 net acres located in Pennsylvania, West Virginia, and Maryland. As of December 31, 2012, the company's proved plus probable gross reserves were 341,072 thousand barrels of oil equivalent, including 148,297 million barrels (Mbbls) of light and medium crude oil; 42,496 Mbbls of heavy crude oil; 14,412 Mbbls of natural gas liquids; 590,702 million cubic feet (MMcf) of natural gas; and 224,500 MMcf of shale gas. Enerplus Corporation was founded in 1986 and is headquartered in Calgary, Canada.