Nebraska Statutes: 23-306
23-306. Irregular tracts of land; survey; field notes; record. The board shall also cause to be entered in duplicate, in suitable books to be provided for that purpose, the field notes of all such tracts of land within their respective counties, wherein shall be described each tract according to survey, and each tract shall be therein numbered to correspond with its number on the maps. One of such books of field notes shall be filed in the office of the county clerk, and the other in the office of the county treasurer.