220 ILCS 5/15-301

(a) Each common carrier by pipeline shall: (1) Keep written accounts and records of its revenues, expenses, contracts, and other activities subject to regulation under this Act in accordance with regulations prescribed by the Commission; (2) Maintain, for a period of 3 years, copies of all accounts and records required by Commission regulations; and (3) Make the accounts and records available for inspection, on request, by an authorized employee of the Commission. (b) Accounts and records kept under this Section shall be kept at an office in the State of Illinois unless the Commission shall have authorized maintenance at a location outside of the State.