MidAmerican Energy Company is an energy company based in Des Moines, Iowa. Its service area includes almost two-thirds of Iowa, as well as portions of Illinois, South Dakota, and Nebraska. Its territory is wholly encompassed by the territory of the Midcontinent Independent System Operator. Major cities in MidAmerican Energys service territory are Des Moines, Sioux City, Sioux Falls, Council Bluffs, Waterloo, Iowa City, and the Quad Cities. MidAmerican Energy Company is a subsidiary of Berkshire Hathaway Energy. MidAmerican Energy was formed in 1995 by the merger of the Iowa-Illinois Gas and Electric Company with Midwest Resources. Midwest Resources in turn, was formed in 1990 by the merger of Midwest Energy and Iowa Resources. Midwest Energy was the holding company for Iowa Public Service company (IPS), the main power provider for northwestern Iowa, while Iowa Resources was the holding company for Iowa Power and Light Company, the main power provider for central and southwestern Iowa.