Maryland Code, Alcoholic Beverages and Cannabis § 16-2703

(a) An individual may possess an alcoholic beverage in an open container on private property described under § 6-322(a)(1) of this article only if the individual possesses and presents the written consent of the owner of the property.

(b) In addition to the prohibitions listed in § 6-321 of this article, an individual may not possess in an open container an alcoholic beverage while on a motorcycle located in the places listed in § 6-321 of this article, unless the individual possesses and presents the written consent of the owner of the property.