Colo. Rev. Stat. § 40-2-111
Each public utility required to pay such fees shall, on or before May 15 of each year, file a return with the department of revenue on such forms as shall be prescribed by the executive director of the department of revenue and the public utilities commission setting forth the gross operating revenues of such public utility from intrastate utility business only transacted in the state of Colorado during the preceding calendar year. Such return shall be executed and verified by two of the executive officers of the utility making the return and shall contain or be verified by a written declaration that it is made under the penalties of perjury in the second degree, and any officer who knowingly and willfully makes and signs a false return is guilty of perjury in the second degree.
C.R.S. § 40-2-111
For perjury in the second degree, see § 18-8-503.