Interstate Power and Light Company, a public utility company, generates and distributes electricity, and distributes and transports natural gas to retail customers in Iowa. The company operates through three segments: Electric Operations, Gas Operations, and Other. It generates electricity from coal, natural gas, and wind energy; and purchases electricity from wholesale energy markets. The company also sells electricity to wholesale customers, including municipalities and rural electric cooperatives in Minnesota, Illinois, and Iowa. In addition, it generates and distributes steam for customers in Cedar Rapids, Iowa; and owns overhead electric distribution lines, underground electric distribution cables, and substation distribution transformers, as well as gas mains in Iowa. The company provides utility services to incorporated communities. It offers electric utility services to retail customers in various industries, such as farming, agriculture, industrial manufacturing, chemical, packaging, and food industries, as well as gas utility services for various industries comprising research, education, hospitality, manufacturing, and chemicals. As of December 31, 2020, it supplied electric service to approximately 495,000 retail customers and natural gas service to approximately 225,000 retail customers. The company was formerly known as Iowa Railway and Light Corporation. The company was incorporated in 1925 and is based in Cedar Rapids, Iowa. Interstate Power and Light Company operates as a subsidiary of Alliant Energy Corporation.