C.R.S. § 39-11-106

(1) To the amount of delinquent taxes there shall be added a fee to cover the cost of advertising, as provided in section 30-1-102 , C.R.S. If the public auction is conducted by means of the internet or other electronic medium, the treasurer may add a fee to cover the cost of conducting the public auction. (2) The treasurer of each county shall deliver his list of all lots or tracts of land for which tax liens are to be advertised for sale to the publisher or printer at least ten days before the date of the first publication.