He said Obanesyan and Torossian had a map identifying fuel stations with pumps that can be operated by the remote.
The men told authorities they had purchased the fuel trailer in Tennessee, Peoples said. They were on their way back to California when they were arrested.
The sheriff said deputies found a large number of blank credit cards in their possession when they were arrested. The case was referred to the U.S. Secret Service, which declined to comment on an ongoing investigation.
Obanesyan and Torossian remain jailed in Custer County in lieu of $250,000 bail. They were charged Monday with grand larceny and possession of burglary tools.