This spatial data layer includes the locations of site leaders administering the Long-Term Agroecosystem Research (LTAR) Network. Locations are indicated by points where LTAR site leads have their public point of contact. If more than one lead exists, more than one point will be shown for the LTAR site. Location types are indicated as: primary, secondary, or collaborator. Primary is the location of the LTAR Principle Investigator (PI) or main research office. To create a map of LTAR points showing only one point per location, symbolize the layer using the “primary” point. Secondary locations are where Co-PIs reside (if different). Collaborator locations are where collaborators reside. The inclusion of collaborators is optional. Some sites have extensive lists of collaborators and have chosen not to include them here. Contact the POC for more information about collaborators. This layer differs from the LTAR Site Location layer in that it is NOT where data are being collected, but rather refers to the institutional identity of the site.