Southwest Gas Corporation (Southwest) is engaged in the business of purchasing, distributing and transporting natural gas to residential, commercial and industrial customers in the southwestern United States. The Company is composed of two business segments: natural gas operations (natural gas operations segment) and construction services. Southwest is also the distributor of natural gas in Nevada, serving the Las Vegas metropolitan area and northern Nevada. In addition, Southwest distributes and transports natural gas in portions of California, including the Lake Tahoe area and the high desert and mountain areas in San Bernardino County. NPL Construction Co. (NPL), a wholly owned subsidiary of Southwest, is a full-service underground piping contractor that primarily provides utility companies with trenching and installation, replacement, and maintenance services for energy distribution systems.