Why are some base map features out of date, misplaced, or no longer there?

USGS personnel involved with The National Map program work with Federal, State, Tribal, and local partners for acquiring data.  The composite base maps are a result of this data acquisition and production effort.  Our base maps accurately reflect data holdings of The National Map, but some features may not be positionally accurate or complete, or up-to-date as desired.  We are working on improvement of methods for both partner provided updates as well as future user collaboration models for data maintenance as required by stakeholders.  Users are encouraged to contact the Service Desk <tnm_help@usgs.gov> to report data problems.