Mont. Code Ann. § 35-2-529

35-2-529 . Action by written consent. (1) Unless limited or prohibited by the articles or bylaws, action required or permitted by this chapter to be approved by the members may be approved without a meeting of members if the action is approved by members holding at least 80% of the voting power. The action must be evidenced by one or more written consents that describe the action taken, be signed by those members representing at least 80% of the voting power, and be delivered to the corporation for inclusion in the minutes or filing with the corporate records.

(2) If not otherwise determined under 35-2-528 or 35-2-532 , the record date for determining members entitled to take action without a meeting is the date the first member signs the consent under subsection (1).

(3) A consent signed under this section has the effect of a meeting vote and may be described as a vote in any document filed with the secretary of state.

(4) Written notice of member approval pursuant to this section must be given to all members who have not signed the written consent. If written notice is required, member approval pursuant to this section is effective 10 days after written notice is given.