C.R.S. § 39-4-104

The division of property taxation, through the administrator, and its employees, shall have the right at any time, upon demand, to inspect the books, accounts, and records of any public utility doing business in this state for the purpose of verifying the information contained in its filed statement and to examine under oath any officer, employee, or agent of such public utility. Any person making such demand upon a public utility on behalf of the administrator shall produce and exhibit his authority to make such inspection or examination.