Archaeology_area layer is based on what is displayed in the PDSD webmap as the Downtown Redevelopment District. The link between these boundaries was probably associated with the Downtown Heritage Incentive District which was removed (for the most part) from the LUC and Development Standards and replaced with the RND Zone. See page 52 of the Historic Preservation Development Standards for one of those lingering references: http://www.tucsonaz.gov/dsd/Codes___Ordinances/DS_Renumbered/DS_9-08_Historic_Preservation_Zone.pdfMost likely, the Downtown Redevelopment District, DHID boundary and this archaeology_area were based on the cbd.shp (central business district). It is not clear what part of the code or Administrative Directive establishes the authority/requirement to review development projects for archaeological impact, but that is what this layer was previously used for until it was replaced with the more encompassing archaeological sensitivity area layer. No edits planned, but is currently used on some maps.tucsonaz.gov web applications.