After the Yellowstone Supervolcano erupted, congress passed the Supervolcano Emergency Authorization Act. Among other things, it authorized FEMA to set up refugee camps such as Camp Constitution, funded reclamation parties salvaging goods within the ashfall areas and checkpoints limiting civilian travel to essentials. When Vanessa Ferguson headed home to Los Angeles from Oklahoma City via I-20 in Texas, she encountered a Status Evaluation Control Checkpoint as the interstate approached I-10. She was forced to stop and justify her trip to a Texas Ranger. She argued she had lived her whole life in L.A. until she moved to Denver shortly before the eruption. She gave her father's telephone number who confirmed her story. The Ranger reluctantly let her proceed.