Maryland Code, Natural Resources § 10-504

(a) A person may not hunt any muskrat, beaver, or otter in any manner except by trapping.  A person may not dig into or in any manner molest or destroy any part of a muskrat, beaver, or otter den or house.  A person may not possess at any time the hide or skin of any muskrat, beaver, or otter which has been caught in any way except by trapping, and any muskrat, beaver, or otter hide or skin which has been punctured by a hole which appears to be a shot or bullet hole shall be prima facie evidence that the muskrat, beaver, or otter was killed illegally.

(b) A person may not possess at any time a light for the purpose of hunting muskrats, beaver, or otter at nighttime.  Possession of a light shall be prima facie evidence that the light was intended for this purpose.

(c) A landowner or the landowner's lessee shall have the exclusive right to trap for muskrats down to the mean low watermark or on marsh land adjacent to the landowner's land.  A person may not enter upon or place traps upon the land without first obtaining the written consent of the landowner or the landowner's lessee.