Mass. Gen. Laws ch. 90B, § 26
(a)
(ii) the operator has in his possession either a document, signed by the owner or lessee of such property or his agent, authorizing the operation of a such vehicle on the property by the operator or valid proof of current membership in a club, association or other organization to which express authorization for the operation of such vehicles on the property has been granted; provided, however, that such operation shall be consistent with the express authorization granted and any restrictions imposed therewith; or (iii) the owner or lessee of the property has designated the area for use by such vehicles by posting reasonable notice of such designation in a manner approved by the director.
No person shall operate a snow vehicle or recreation vehicle on publicly-owned property except on trails marked and designated for use by such vehicles, or without the express permission of the owner.