All across the continental U.S. as well as in Alaska and Hawaii there is a network of survey monuments which are bronze disks about 8 to 10 centimeters in diameter set in rock or permanent structures. These monuments are survey reference points that have been set by licensed surveyors since 1879 and are the basis for the United States PLSS (USPLSS). The reference points, or control stations, are generally set at section corners, quarter-section corners, or center of sections.
A dossier sheet is a record of a USPLSS control station, or witness corner. Each sheet contains an identification of the corner and a sketch of the station in relation to important features in its immediate vicinity as an aid to its recovery in the field. The dossier sheets also show all witness monuments and ties, monument coordinates (NAD27) and elevations (NGVD29), a surveyor's affidavit, and the land surveyor's registration seal and signature.
Ozaukee County's cadastral base map that utilizes these section corner and quarter corner survey monuments as reference points to constantly update and include the following information:
All easement descriptions when found
All property boundaries as originally platted when identifiable
All property measurements where available
All real property boundaries
All road, street, highway right-of-way lines
All tax key numbers
Area of parcel in acres when appropriate
USPLSS corner monumentation is complete for Ozaukee County. The dossier sheets are available on-line for most corners in the county.