Geographic Information Systems (GIS)


Purpose & Definition

Under the Superfund program, and with a grant from the Atlantic Richfield Company (ARCO), the Butte-Silver Bow Geographic Information System (GIS) Department was initiated in 1990-91. The GIS Department is charged with providing timely and accurate GIS information to all Butte-Silver Bow local government departments, as well as various state, federal, and private entities.

The textbook definition of GIS is "an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information."  Much of the geographic information maintained by Butte-Silver Bow  is sourced from several legacy documents, often hard copy maps, later digitally generated using ARCInfo GIS software then plotted on an inkjet plotter.  Today the Butte-Silver Bow  GIS department relies on several tools and systems of data collection and storage.  Mobile Global Positioning System (GPS) capable devices and digital databases serve to update and maintain the department’s expansive data collection.

Plot Maps

Data or information used to plot maps are derived from a variety of sources. Various scale plan metrics (or topology) for features such as roads, streams, railroads, building roof prints, contours, etc., are produced from aerial photography, which has been photogrammetrically processed by various commercial vendors or by state or federal government mapping agencies.

Political and administrative boundaries such as fire districts, legislative boundaries, precinct boundaries, and commissioner districts were originally created by digitizing the original hard copy maps and using the recorded legal boundary descriptions for reference.

Land Records Data

At the heart of Butte-Silver Bow lies the ownership or land records data. Land records data, known also as the cadastral or ownership base, have long been generated using existing Montana Department of Revenue parcel base maps, mining claims maps, and property legal descriptions. Information about each parcel is contained in the Montana Department of Revenue’s Computer Assisted Mass Appraisal System (CAMA) data, which is updated on a regular basis.

Data Acquisition

In combination with the CAMA data described above, the land records data are used for both mapping purposes and for producing reports listing information such as ownership, addresses, assessed valuation, building information, zoning, and so on. Acquisition of this data was driven by the necessity for Butte-Silver Bow, along with ARCO and the Environmental Protection Agency (EPA), to be able to identify properties affected by or affecting Superfund sites. Butte-Silver Bow  has completed digital land records for all the urban area and portions of the neighboring communities and rural areas in Silver Bow County as well as selected data for the Anaconda-Opportunity-Warm Springs Superfund area in Deer Lodge County.

Partial List of Data Available from GIS

The following data is available for public inquiry and/or for supplying a digital, interactive, or physical map:

  • Zoning, growth, and master plan boundaries
  • Administrative and political boundaries (fire districts, school districts, legislative districts, precincts, commissioner districts, etc.)
  • Topologic features (roads, hydrography, buildings, railroads, contours, wooded areas, etc.)
  • Infrastructure (water mains, sanitary and storm sewer lines)
  • Parks & Recreation (parks, fields, trails, and trailheads)
  • Historic information and features
  • Miscellaneous other data (Inquiry with GIS Department)

Data Available from the Land Records and Clerk of Recorder Departments at Butte-Silver Bow:

  • Ownership and deeds
  • Plats maps
  • Certificate of surveys
  • Mining claims
  • Property legal descriptions

Data Available from the Planning Department at Butte-Silver Bow:

  • General ordinances and zoning 
  • Building permits
  • Building codes & code enforcement
  • Address assignment and inquiry

Other Data Sources referenced outside of Butte-Silver Bow through partnering agencies:

  • Bureau of Land Management - BLM
  • Butte-Silver Bow Public Archives
  • Environmental Protection Agency (Superfund)
  • Montana Cadastral
  • Montana Department of Natural Resources - DNRC
  • Montana Department of Transportation - MDT
  • Montana GIS Clearinghouse
  • Montana State Library
  • Natural Resource Information System - NRIS
  • Public Land Survey System - PLSS
  • United States Census Bureau
  • United State Forest Service - USFS
  • United State Post Office (addresses)

Please visit our Maps & Related Data page above to view and download maps available on our website.