National Fuel Gas doesn't cover the nation, but it does touch all the bases in its industry: The company explores for, produces, stores, transmits, and distributes natural gas. The diversified energy concern's public utility, National Fuel Gas Distribution (almost half of the company's annual sales) distributes gas to more than 728,000 customers in New York and Pennsylvania. National Fuel Gas has gas exploration, production, storage, and transportation units; it also engages in energy marketing, timber processing, and independent power activities. In 2015 oil and gas subsidiary Seneca Resources reported proved reserves of 2.1 billion cu. ft. of natural gas and 33.7 million barrels of oil.