C.R.S. § 29-3-115

(1) A lease may grant the user of a project an option to purchase all or a part of the project at a stipulated purchase price or at a price to be determined upon appraisal as is provided in the lease. (2) The option may be exercised at such time as the lease may provide. (3) The county or municipality and the user may agree and provide in the lease that all or a part of the rentals paid by the user prior to and at the time of the exercise of such option shall be applied toward the purchase price and shall be in full or partial satisfaction thereof.