Airspace designated for hazardous military activities, such as live weapons training. All aircraft not associated with these activities are restricted from entry. This layer is a member of the "Military" feature dataset, which contains layers related to military installations and flight training areas in the state of Maryland. Data source: Military Aviation and Installation Assurance Siting Clearinghouse website (https://www.acq.osd.mil/dodsc/about/maps.html) Last updated: 2020. Recommended data update schedule: yearly Contacts sources: websites for the military installation to which each restricted area belongs. Recommended to check for updates when checking for new restricted area data, approximately yearly.