C.R.S. § 1-7.5-209

All identification envelopes and mail ballots rejected by the election judges in accordance with section 1-7.5-204 must be returned to the designated election official. All mail ballots received by the county clerk and recorder or designated election official after 7 p.m. on the day of the election, together with the rejected mail ballots returned by the election judges as provided in this section, must remain in the sealed identification envelopes and may be destroyed as provided in section 1-7-802 .