El Dorado is the seat of Butler County, northeast of Wichita on the Walnut River. It was a county town like any other until the El Dorado oil field was found in 1915 and turned it into an oil town. There is still a refinery working in El Dorado, and Butler Community College is here as well.
What that history left is a town with more working buildings than most places its size: shops and service bays, warehouses, and the larger buildings a county seat collects, alongside the houses. So the equipment runs wider than in a commuter suburb — make-up air and paint booths in the shops, boilers and chillers in the bigger buildings, and furnaces, air conditioners and heat pumps in the homes, some of them past the end of the gas line.