Can I limit the spatial extent of reference data layers?
Reference data layers are loaded to projects to include features that intersect a rectangular “bounding box” delineated as one degree latitude and longitude beyond the outer limits of a project area. Including these data is useful for providing information about your project context. You may want to limit the extent of reference layers, however, for more focused data analysis and mapping. To do so, create a filtered selection of reference data layer features within a project area by applying a join filter, using the Project Area layer as the join layer. Then, save the selection as a new filtered layer. See Filtering and Joining Data for steps on using join filters and saving filtered layers.