Surveying and Mapping The BLM has extensive current and historical information about land ownership and use in the United States. The agency maintains cadastral survey and historical data on lands patented, along with information on the mineral estate, resource conditions, and permits or leases on Federal lands. BLM is also a major user of geographic information systems (GIS) to analyze the data for millions of acres of public lands.  Resources National Pages National Cadastral Surveying Page The BLM is the Federal Government's official record keeper for over 200 years' worth of survey records. Find out about what's involved in this daunting task; includes links to career information and General Land Office records. Geographic Coordinate Data Base Home Page A collection of geographic information representing the Public Land Survey System (PLSS) and some non-PLSS surveys of the United States; includes links to the National Integrated Land System (NILS) and GeoCommunicator, the publication site for NILS. General Land Office Records Live access to Federal land conveyance records for the Public Land States and image access to more than three million Federal land title records for Eastern Public Land States, issued between 1820 and 1908. GIS: A New Way to See Science & Children article that introduces Geographic Information Systems (GIS) and their applications to natural resources decision making; includes classroom activities. State Pages Alaska - Division of Cadastral Survey Includes links to the history of surveying in Alaska up to the present day. Arizona - Maps, Plats, and GPS Data Colorado - Cadastral Survey Home Page Colorado - The 14 Steps in Cadastral Survey Illustrated description of the 14 steps that BLM must follow to complete a formal survey. The icons describe each step in detail. Geospatial Data and Metadata On Line for BLM Colorado Geographic information system (GIS) data have been collected and are used to support BLM base mapping needs and resource management programs; includes on line maps. Montana - Cadastral Survey Home Page Includes links to historical cadastral surveying photos and state maps through GDCB. Nevada - Cadastral Surveying Home Page Utah - Cadastral Survey Home Page Wyoming - Geographic Information Systems Site Links to GIS data, current projects, and images of maps.