N.M. Admin. Code § 11.21.1.15
All meetings of the board (whether general, special or emergency) and all rulemaking, unit determination, and prohibited practice hearings before the board or a hearing examiner of the board shall be audio- recorded, or, upon order of the board may be transcribed, except that board meetings or portions thereof lawfully closed shall not be recorded or transcribed, unless so directed by the board. Following the board's approval of the minutes of a meeting of the board, the minutes shall become the sole official record of the meeting, and the audio recording of the meeting may be erased. The director shall keep the audio recordings of the rulemaking, unit determination, and prohibited practices hearings for a period of at least one year following the close of the proceeding in which the hearing is held, or one year following the close of the last judicial or board proceeding (including any appeal or request for review) related to the case in which the hearing is held, whichever is later, or such longer period as may be required by law. No recording shall be made of any mediation proceeding, settlement discussion, or alternative dispute resolution effort except by agreement of all parties and participating officials. The board's recording or transcript shall be the only official record of a hearing.
N.M. Admin. Code § 11.21.1.15