Minn. Stat. § 204C.25: DISPOSITION OF BALLOTS.

After the count and the summary statements have been completed, in the presence of all the election judges, the counted, defective, and blank ballots shall be placed in envelopes, and the envelopes shall be sealed. The election judges shall sign each envelope over the sealed part so that the envelope cannot be opened without disturbing the continuity of the signatures. The number of ballots in each envelope, the name of the town or city, and the name of the precinct shall be plainly written upon the envelopes. The number and name of the district must be plainly written on envelopes containing school district ballots. The spoiled ballots shall be placed in separate envelopes and returned with the unused ballots to the county auditor or municipal or school district clerk from whom they were received.