Colo. Rev. Stat. § 32-9-131
The payment of district securities may be secured by the specific pledge of the proceeds of sales taxes or revenues, or both such taxes and revenues, of the district, as the board may determine. Revenues or sales taxes pledged for the payment of any securities, as received by the district, shall immediately be subject to the lien of each such pledge, without any physical delivery thereof, any filing, or further act, and the lien of each such pledge and the obligation to perform the contractual provisions made in the authorizing resolution or other instrument relating thereto shall have priority over all other obligations and liabilities of the district, except as may be otherwise provided in this article or in said resolution or instrument, and subject to any prior pledges and liens theretofore created. The lien of each such pledge shall be valid and binding as against all persons having claims of any kind in tort, contract, or otherwise against the district, irrespective of whether such persons have notice thereof.
C.R.S. § 32-9-131