Preserving Minnesota’s GLO Field Notes – Update
By John Hoshal, MnGeo
Are we done yet?
In the Consortium’s Summer 2010 issue I announced that the Minnesota Historical Society had awarded a Historical and Cultural Heritage Grant to MnGeo to scan, index and increase access to Minnesota’s General Land Office (GLO) Field Notes. These unique documents were created between 1847 and 1911 by the U.S. Surveyor General’s Land Office and continue to serve as the legal foundation for all land ownership in the state. I am pleased to report that on June 30, 2011, MnGeo delivered to the Historical Society a 24-terabyte disk array containing digital copies of Minnesota’s original survey field notes and supplemental surveys (island, tribal land, railroad, and transportation) in TIFF and JPEG2000 formats.
During the project, MnGeo and Mn/DOT staff – on mobility assignment at MnGeo – reviewed and indexed nearly 305,000 images captured by its scanning vendor, Perfect Image Inc. Each page was carefully scanned at approximately 640 dpi, in 24-bit color with extra attention given to pages where text rolled into the volume’s gutter.
How do I access the field notes?
In a unique partnership with the U.S. Bureau of Land Management (BLM), Minnesota’s digital field notes, supplemental surveys and GLO plats will be accessible to the public through BLM’s national Land Records website. This site allows a user to search and download records by document type, location and identifier, including the original surveyor. BLM hopes to make Minnesota’s data available by November 2011.
MnGeo is also updating its GLO website to improve access to the original survey plats scanned in 2004. New spatial selection tools for the plats will allow a user to more easily select a township, view or bulk download the plat images, or connect immediately to BLM’s records for that township.
While preparing to link the GLO plats to the field notes, staff created a georeferenced version of the maps. Staff registered each document to real-world coordinates using township corner control points. MnGeo will make these JPEG images available through its GLO website.
Minnesota Historical and Cultural Heritage Grants are made possible by the Minnesota Legislature from the Arts and Cultural Heritage Fund created with passage of the Clean Water, Land and Legacy Amendment to the Minnesota Constitution in November 2008. Grants are awarded to support projects of enduring value for the cause of history and historic preservation across the state.