Colo. Rev. Stat. § 30-26-303
When it appears to the board of county commissioners upon examination of the books and accounts of the county treasurer that there are sufficient funds in his hands to the credit of the redemption fund to pay in full the principal and accrued interest of any of such bonds, it is the duty of such board immediately to call in and pay as many of such bonds and accrued interest thereon as the funds ascertained to be on hand will liquidate, and said board shall thereupon cancel such redeemed bonds and all uncanceled interest coupons issued therewith. The bonds shall be called in and paid in the order of their issuance, as nearly as may be practicable, and when it is desired to redeem any of such bonds by said board it shall cause to be published for thirty days in some newspaper at or nearest the county seat of the county a notice that certain county bonds, specifying the number and amounts, will be paid upon presentation, and at the expiration of such thirty days such bonds shall cease to bear interest.
C.R.S. § 30-26-303
For clarification of terms and requirements for notice by publication, see part 1 of article 70 of title 24 .