Lillian, Ohio is a fictional town of about 12,000 people in the state of Ohio in the United States of America. The town is located right next to the real life town of West Alexandria, Ohio as it is shown on a map in the movie. In 1979, a U.S. Air Force train derailed and a captive alien was freed. The creature then roamed the town, stealing mechanical equipment and kidnapping people. The Air Force occupied the town and ordered an evacuation (by cover of a wildfire) for "Operation Walking Distance." Many buildings were destroyed in the battle to recapture the alien.
The town has the average amenities of a small Ohio town: school, factories, gas stations, and restaurants. The factories present in the town are a steel mill where Joe Lamb's mother dies in February of 1979. There is also a chemical plant present in the town as well and these are surrounded by the Lillian suburbs. It also has a sheriff's office with a staff that attempted to solve the mystery behind the train crash.