A cadastre, or cadaster, is a comprehensive recording of the real estate or real property of a county, province, or country; cadasters are frequently represented graphically in a cadastral map. A cadastral map then is a map that “shows the boundaries and ownership of land parcels.” Cadastral maps will sometimes include additional details, such as: Certificate of Title numbers, positions of existing structures, section or lot numbers and their respective areas, and street names.

In ancient times, Rome’s Emperors ordered the creation of cadasters to “recover state owned lands that had been appropriated by private individuals, and thereby recover income from such holdings.” The use of cadastres fell out of practice with the fall of Rome; written descriptions of the extent and dimensions of parcels was used instead. However, with the dawn and eventual spread of capitalism, Renaissance Europe saw the resumption of cadastral maps as a “a tool to determine and express control of land as a means of production…first privately in land disputes and later [as a] governmental practice [for] more precise tax assessment.”

Plat maps are a type of cadastral map.

Metsker's Atlases of Oregon Counties, 1929-1988
The Metsker's Atlases of Oregon Counties consist of 66 atlases and include one or more atlases for all 36 Oregon counties that depict property owners and donation land claims. The bulk of the atlases were published in the 1930s-1950s. Each atlas includes an index map. The number of maps per atlas varies from 20 to 300; however, most of the atlases have fewer than 100 maps. The maps are at a scale of 2 inches = 1 mile. In addition to property boundaries, the maps show roads; railroads; streams, rivers, and water bodies; and schools.

Central and Eastern Oregon Township Plats, 1858-1939
The Central and Eastern Oregon Township Plats consist of reproductions of the original manuscript plat maps for townships in regions of Oregon east of the Cascade Mountains prepared by the U.S. General Land Office and the U.S. Surveyor General; most of the maps were prepared in the 1870-1890s. Each township of 36 square miles is on a separate sheet. Most sheets have a scale of about 1:31,680 or 2 inches = 1 mile; the remainder are at a smaller scale of about 1.5 inches = 1 mile. These plats cover from Townships 4N to 41S and Ranges 6E to 37 E. Regions depicted in this collection include the Umatilla River basin, Blue Mountains, John Day River basin and tributaries, Snake River, Deschutes River, and Klamath Basin. Boundaries of the Umatilla, Malheur, and Klamath Indian Reservations are shown on the plats. Plats for the Vale and Owyhee Irrigation Projects prepared in the 1930s are included. Several of the plats show mining ditches and placer mining claims in the John Day River basin. The Klamath River, Klamath Lakes and associated marshes, Tule Marsh, and Modoc Lake as well as Fort Klamath and the Klamath Irrigation Project are depicted. The plats show section lines as well as natural features and vegetation such as prairie; timber, soil types; rivers, streams, sloughs, and wetlands; and fields. The maps include some topographic features. Most of the plats include a narrative description indicating if the township is appropriate for grazing or cultivation, the soil quality, availability of water, and type of timber. Wagon trails and military roads are shown on the plats as well as land claims. This collection consists primarily of single copies of each township plat; however, there are some townships represented by multiple copies of the same plat or different editions of the same township. These survey plats, as well as field note records for these townships, are available online through the Land Status and Cadastral Survey Records website prepared by the Bureau of Land Management's Oregon State Office.