Colorado Revised Statutes Title 39. Taxation § 39-11-107. Erroneous assessments--abatement

It is the duty of the treasurer of each county, before making sale of tax liens on any lots or land for unpaid taxes, to carefully examine and compare the delinquent list with the assessment roll and block books in his office, and to omit from such sale the tax liens on all lots and lands doubly or erroneously assessed, insofar as he is able to ascertain the same, and to make an itemized report to the board of county commissioners of his county showing such double or erroneous assessment. The board of county commissioners, on receipt of such itemized report, by resolution to be entered in its proceedings, shall abate the taxes levied upon such double or erroneous assessments.