Pacific Cadastral Data
Information System (GIS) Data and Maps
The Mapping & Boundary Branch
performs mathematical offshore boundary location computations and prepares
Official Protraction Diagrams (OPDs), and
Supplemental Official OCS Block Diagrams (SOBDs) depicting OCS Block information, the Submerged Lands
Act Boundary (aka - State Seaward Boundary), Limit of "8(g) Zone", the
Continental Shelf Boundary (CSB), which marks the limit of U.S.
jurisdiction for offshore mineral development, and corresponding area
measurements. The analytical procedures employed and the computer programs
utilized to perform various offshore boundary geometric computations are
described in OCS
Report MMS 99-0006.
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A standard OPD is 1 degree in latitude by 2 degrees in
longitude (at lower latitudes: 0 - 48 degrees). At higher latitudes (48 - 75
degrees) such as Alaska and northern Washington, OPDs are 3 degrees wide. OPD
limits usually approximate the standard 1:250,000 scale U.S. Geological Survey
topographic map series. The OPDs are numbered using the United Nations
International Map of the World Numbering System. OPD names usually coincide with
standard topographic sheet names when diagrams include land areas. OPD sheet
names relate to land features, or to hydrographic features contained within the
limits of the diagram. Shoreline planimetric detail is shown when it falls
within the limits of a diagram. Older OPDs were prepared on mylar with manual
cartographic methods and then scanned into Adobe .pdf files. Newer OPDs were
prepared electronically and converted to Adobe .pdf files.
NOTE: OPDs offshore of Oregon and Washington that show the Submerged Lands Act and Section 8(g) Zone boundaries do not reflect post-2010 shoreline changes. The Submerged Lands Act and 8(g) Zone boundaries offshore of California were permanently immobilized by the U.S. Supreme Court on December 15, 2014.
A Supplemental Official OCS Block Diagram
(SOBD) is prepared for each block intersected by an offshore boundary (Submerged
Lands Act Boundary, Limit of "8(g) Zone", National Marine Sanctuaries, etc.).
Note that not all OPDs contain such boundaries, therefore not all
OPDs have SOBDs associated with them. All the SOBDs for a given
OPD are zipped into a single file for downloading. The zip files will contain
the most recent version, but older historic versions may also be included for
reference. For the purpose of future Lease Sales always be sure to use the
most recent version.
NOTE: SOBDs offshore of Oregon and Washington do not reflect post-2010 shoreline changes. The Submerged Lands Act and 8(g) Zone boundaries offshore of California were permanently immobilized by the U.S. Supreme Court on December 15, 2014.
Composite Block Diagrams
(CBDs) show NAD 27 lease information portrayed on the NAD 83 cadastre. Not all
OPDs have CBDs associated with them.
Image File Formats
current approved revision for each Pacific Region OPD and SOBD may be viewed and
downloaded from the list below. OPDs are offered in Adobe (.pdf) format. SOBDs
are available as Adobe (.pdf) files that have been compressed with WINZIP. Adobe
(.pdf) files may be viewed with the free Adobe
The various boundaries are also
offered as ESRI ArcGIS shapefiles. Shapefiles can be viewed with the free ArcGIS
Explorer viewer, ArcGIS, or a variety of other GIS systems. The shape files
have been zipped using WinZip.
Note: The precise
coordinates of a GIS file can be altered slightly by various GIS functions. For
that reason, these GIS files are not an Official Record for BOEM offshore
boundaries. Only the coordinates shown on Official OPDs, CBDs, and SOBDs
constitute an Official Record for offshore coordinate values.
All coordinates are in NAD 83. Pacific Region leases and
cadastre data from before 1994 were mapped using the North American Datum of
1927 (NAD 27). These new NAD 83 files do not represent a conversion, but rather
a complete re-grid. For further details, see Project Plan for
Implementing NAD 83 in the Bureau of Ocean Energy Management:
Area Acreage Statistics as of 10/02/2008
Area Descriptions as of 01/2002
Additional Pacific Data Sources