Chief Oil & Gas was founded; its early focus was on reserves in the Bend Conglomerate reservoir of North Texas.
Chief Oil & Gas changed its focus to the Barnett Shale and drilled its first Barnett well.
Chief Oil & Gas began drilling horizontal wells in the Barnett Shale.
Chief Oil & Gas became the second largest producer in the Barnett Shale with more than 250 wells drilled, 200,000 acres leased, and production surpassing 100 million cubic feet of natural gas per day.
Chief Oil & Gas sold the majority of its leasehold and production to Devon Energy. Chief expanded into other prospective fields while retaining a small position in the Barnett Shale. Chief sold its midstream business to Crosstex.
Chief Oil & Gas accumulated acreage in the Marcellus.
With close to 600,000 acres of net leasehold, Chief Oil & Gas became one of the largest leaseholders in the Marcellus Shale. Chief Gathering was established as a sister company to Chief Oil & Gas to build the infrastructure to meet the demands of the northeastern markets. Chief exited the Barnett Shale with a sale to Quicksilver.
Chief Gathering sold all the Marcellus pipeline and midstream assets to Penn Virginia Resource Partners (PVR). Chief Oil & Gas maintained its Marcellus leasehold in northeastern Pennsylvania.
Chief Oil & Gas divested non-operating acreage in Bradford, Lycoming and Sullivan Counties to BKV Chelsea LLC.
Chief Oil & Gas achieved 1Tcf gross production milestone in the Marcellus Shale.
Chief Oil & Gas reached its 10-year milestone of Marcellus operations.