Entergy is into energy. The integrated utility holding company's subsidiaries distribute electricity to 2.8 million customers in four southern states (Arkansas, Louisiana, Mississippi, and Texas) and provide natural gas to 199,000 customers in Louisiana. Entergy operates 15,500 miles of high-voltage transmission lines and 1,500 transmission substations. In addition, the company has interests in regulated and nonregulated power plants in North America that have a combined generating capacity of about 30,000 MW (including nearly 10,000 MW of nuclear power). Entergy is one of the largest nuclear power generators in the US.