An area depicted as surface ownership parcels dissolved on the same ownership classification. Changes in basic ownership are tracked over time. This feature class tracks the history of changes to these features through time. As a result, features overlap each other because different versions of the same feature occupy approximately the same place. Usually, the features that were active at a particular time should be selected before any analysis or displays are done. By selecting only the features active at a particular time, overlaps are eliminated. The current version of the features can be found with this query: EFFECTIVEDATE <= sysdate and EXPIRATIONDATE > = sysdate. The features current as of a specific date, for example 10/15/2015, can be found with this query: EFFECTIVEDATE < date '2015-10-15' and EXPIRATIONDATE >= date '2015-10-15'.

It is important to note that the attribute BASICOWNERSHIPID is not persistent over time and can't be used to track changes over time. Unique combinations or REGION, FORESTNAME, and OWNERCLASSIFICATION define the multi-part polygons and the EFFECTIVE_DATE and EXPIRATION_DATE apply to these polygons. Polygons outside the administrative forest boundaries cannot be assigned a FORESTNAME and have null value for that attribute. Polygons assigned a null value for FORESTNAME can have any value of OWNERCLASSIFICATION.

Changes to this dataset occur for a variety of reasons: land exchanges, land purchases, or land sales; correction of errors; vertical integration to match other boundaries. Questions can be directed to SM.FS.data@usda.gov