I don't know why the state legislature passed the law, but there is a statement at the top of the page I'll paste below. It is the only drone law in Maine AFAICT, passed in July of 2015. It's my opinion that they didn't want to spend any time or resources crafting a policy that would accommodate any sUAS use by the public, so they just banned them. Maine does have large tracts of 'Public Reserved Land' (mostly forest) that is not affected by the ban.
MAINE STATE PARK POLICY BUREAU OF PARKS AND LANDS
Drones, Unmanned Aircraft System (UAS)
Public safety, privacy of park users, liability, protection of wildlife, and noise are the primary factors considered in formulating this policy. The general use of drones (UAS) is prohibited in Maine State Parks, Historic Sites, or DACF Boat Launches without direct oversight and guidance of an approved law enforcement agency or by the issue of a Special Activity Permit.
Commercial Use
Commercial use of drones (UAS) is prohibited.
Law Enforcement Use
Maine law enforcement agencies including Maine State Police, Maine Warden Service, Maine Marine Patrol, Maine Forest Service, Maine County Sheriff Departments, and Maine Municipal Police Departments are authorized under this policy to provide oversight and guidance for search and rescue missions or training under the following circumstances:
1. The mission of all UAS use must be for search and rescue operations or training.
2. Law enforcement agencies may coordinate with an outside agency that is licensed, FAA
registered, and certified for the purposes of search and rescue or reconnaissance
necessary to effect recovery of an individual.
3. The collaborating law enforcement agency must contact the Bureau of Parks and Lands
immediately when any use of UAS from Bureau of Parks and Lands property is used and
must be present, on site, at all times that the UAS is used.
4. The law enforcement agency will be required to notify the Park, Regional office, or
Central office of the Bureau of Parks & Lands regarding each mission immediately or prior to the start of the mission.
State Employee Use
State employees or their representatives in the official conduct of their duties and with prior written permission from the Bureau are exempted from this policy.
Special Activity Use
Under certain rare circumstances Special Activity Permits may be issued. Individuals wishing to pursue the use of drones in a Maine State Park can apply for a Special Activity Permit. The issue of a Special Activity Permit will be processed through the Parks regional office containing a full description of the activity along with an appropriate Certificate of Liability Insurance listing the State of Maine, Bureau of Parks and Lands, and the specific park, as co-insured. The permit will be valid only after the signature of the Regional Manager has been obtained.
