Okay, so I overlayed the detail parcels on the polygon that you highlighted and it is in fact an empty space with no ownership data in between three polygons of Colville NF-owned parcels acquired on three separate dates. Not sure what to do with that.

If you'd like to inspect it in OSM, the data I used can be pulled from here (filter Colville National Forest using the NFSLANDUNITNAME field): https://data-usfs.hub.arcgis.com/datasets/b0c872fdf10c45f89d7d96e2c106f709_0

