Public Service Company of Colorado, together with its subsidiaries, engages in the generation, purchase, transmission, distribution, and sale of electricity in Colorado. It also purchases, transports, distributes, and sells natural gas to retail customers; and transports customer-owned natural gas. The company serves large commercial and industrial electric retail customers in various industries, including fabricated metal products, and oil and gas extraction; and small commercial and industrial customers in real estate and dining establishments. It provides electric utility services to approximately 1.4 million customers; and natural gas utility services to approximately 1.3 million customer