For the purpose of providing for the acquisition of necessary ground therefor and purchasing, erecting, constructing, or reconstructing such building and for the necessary equipment therefor, the county, city and county, city, or town may issue bonds to be known as liberty memorial bonds, to be issued and sold as provided by law; and the county, city and county, city, or town shall provide for portions of such bonds to become due at different, definite periods, but none in less than five nor more than fifty years from the date of issue.
C.R.S. § 29-6-102