No sentencing date has been set for 64-year-old Jimmie Doyle Farris of Odessa, who remains in custody.
Farris pleaded guilty Monday in Midland to a federal arson charge linked to fires set between last May 28 and June 15.
Investigators say the fires in Midland and Ector counties were close to oilfield operations. Fire marshals became suspicious when Farris kept turning up at the burning sites, including cases where he called 911.
Farris was put under surveillance. He was arrested in June after officers noticed smoke in a field where Farris had just stopped.
Farris pleaded guilty to maliciously damaging real property by means of fire.