Secured Areas are included for context only, they were not used in the analysis. To improve map drawing times, secured areas are disabled when zoomed out further than 1:1,000,000. Labels noting the name of the secured area parcel turn on automatically when zoomed in closer than 1:50,000.

The TNC secured land data strive to include all permanently protected lands in the eastern 18 U.S. states and is compiled annually from over sixty sources. For the most part, it is a combination of public land information maintained by each state, and private conservation land information compiled by the Nature Conservancy’s state field offices. Nature Conservancy staff in each state office compile the dataset for their state, assign the securement status to each tract, and fill out the other standard fields (for example designation, acres, ownership type) . The completed state dataset are then compiled by the regional science office and quality checked for consistency and discrepancies. Each year the data set is posted for public use. It also contributes to the Protected Areas Database U.S. (PAD US) and National Conservation Easement database to become part of the national datasets of protected lands.