Map Categories

Commission Drawn Series
Internal maps, created by our Boundary staff, illustrating the Commission’s land and water boundaries.

CX and CMF Series
Survey or engineering drawings and maps that are essential for boundary research.

LR Historical Map Series
Land and waterway surveys illustrating shoreline, tidelands, and shallow submerged lands, maps monitoring the navigability of waterways, and maps illustrating existing conditions before and after completion of waterway projects.

Historic Hydrographic & Topographic Maps/Surveys
Mapping of waterways and their intersection with land. Hydrographic surveys depict the shoreline and the adjacent waterways, including rivers, bays, and the Pacific Ocean. Topographic surveys depict the same shoreline as shown by the Hydrographic surveys but their mapping extends several hundred yards inland and shows the detailed shape of the shoreline.

Historic Quadrangle “Quad” Maps
Topographic maps prepared by the US Geodetic Survey that show areas ranging from 50 square miles to over 8,000 square miles. Most of these historical maps predate the 1950s, depict conditions at the time of the surveys, and are used as resources for the investigation of historic waterways and landforms.

Swamp & Overflow Land Survey Maps
24” x 24” maps bound in map books that are initial research tools used to spatially relate the S&O (swamp and overflow) surveys in a particular area. These maps depict areas that are fit for cultivation using reclamation and are often used to determine riparian rights for water usage. They are also used as the base for private title interests from the State to an individual entity.

Spanish & Mexican Land Grants
Staff uses these maps, which illustrate the areas affected by these grants, to make boundary determinations along a water body that is either within or adjacent to a Rancho. These maps show the initial subdivision of the lands in California at the time of Statehood. The areas depicted on these maps show the extent of private land claims from the Mexican government.