Survey Records Available from the Information Center
GLO/BLM Field Notes and Survey Plats from 1850 to the present - Field notes contain a complete description of each mile surveyed, every monument set and every bearing tree scribed. Plats show graphic representation of information contained in the field notes.
Mineral Surveys, Field Notes and Plats 1850-present - Records of mineral surveys approved by the GLO or BLM Colorado.
Tract books - books that note all transactions affecting public lands from the 1860s to July 1, 1965. The local land offices in Colorado maintained these books daily. A separate set of tract books was maintained daily by the GLO in Washington, D.C. Microfilm of both sets are available in the Colorado State Office.
Historical Indexes and Master Title Plats - In 1965, tract books were superseded by the historical index, a chronological listing of actions affecting land title. The HIs are maintained daily in the Colorado State Office. The graphical representation of the HIs is on the master title plats. Both HIs and MTPs may be viewed from microfilm (aperture cards) in the Colorado State Office. Each BLM Field Office has copies of the HIs and MTPs for its area of responsibility.
Survey Records Online
For information available online, visit the BLM General Land Office Records Automation web site.