According to a press release by the department, the skimmer was found Thursday, at the Miller's Food Mart No.1 at 1250 US-90.
The department said the skimmer was found on gas pump number five after a customer filed a complaint to Liberty police.
Consumers who have paid at the pump at this gas station are urged to monitor their credit and debit accounts.
To avoid falling victim to a skimmer, experts suggest using the gas pump closest to the store and checking for Bluetooth signals that have an I.D. with a string of numbers and letters.