Web map services allow your applications to connect to and use on-line GIS datasets.  The State Library offers the services listed below.  Anyone may view the services in their web browser by clicking on the service names below and then choosing the ArcGIS.com map viewer link near the top of the service's home page.

• Note: The presence of a map service, the data schema, and the data itself are subject to change as resources allow and the data or the service improves and is updated. To stay informed about changes to these web map services, join the MAGIP listserv (free), monitor the Clearinghouse home page news feed, and connect with us via Facebook. Direct questions about a specific web map service to the respective MSDI theme steward/lead.
• ArcGIS Desktop Users may use this URL -- https://gisservicemt.gov/arcgis/rest/services/ -- in the "Add ArcGIS server" dialog box to access the main list of services.  You may also use the View In Arcmap link on the service home pages listed below to add the services to your map documents. See the ArcGIS Help for assistance with connecting to services from ArcMap.
• Web Mercator projection:  Unless otherwise noted these services use the Web Mercator coordinate system, which facilitates their incorporation into web map applications.  Users of ArcMap must make sure that the coordinate systems of their data frames are never set to Web Mercator if they want to perform any kind of measurements.  Most web applications understand that the map scale varies as you move north and south in this coordinate system, but ArcMap mostly does not.  Measurements made in Montana will be from 40 percent to 100 percent too large if they are made using the Web Mercator projection.

Montana Spatial Data Infrastructure Services

• Boundaries:  This contains the layers of the Montana Administrative Boundaries Framework, which includes the State boundary, counties, school districts, incorporated cities and towns, Indian reservations, weed management districts, and tax increment financing districts. 
• Cadastral:  This shows the Montana Cadastral Framework, with the boundaries of Montana's tax parcels. 
  • Public Land Survey:  This shows the Montana Public Land Survey System of townships, ranges, sections, and section subdivisions.
  • Public Lands:  This shows Public Lands that are recorded in the Montana Department of Revenue's tax appraisal database. 
  • Conservation Easements:  This show private lands parcels on which a public agency or qualified Land Trust has placed a Conservation Easement in cooperation with the land owner. 
• Geographic Names:  This contains the Montana Geographic Names Framework.
• Hydrography:  This shows the lakes, streams, and other water features of the Montana Hydrography Dataset.
• Land Cover:  This shows the Montana Land Use/Land Cover Framework.
• Managed Areas:  This shows public and private Managed Areas and information on special land designations.
• Mapping Control:  This show the Mapping Control Framework submitted by registered land surveyors or GIS professionals
• Orthoimagery (Air Photo) Services showing the National Agricultural Imagery Program (NAIP) photos for 2019, 2017, 2015, 2013, 2011, 2009, and 2005 are available. The 2009-2019 services may be displayed as color infrared images by choosing to show bands 4, 1, and 2 as the red, green and blue bands. The 2005 service is only natural-color, but a separate service is available for infrared images taken in 2005 and 2006.
• Roads:  This shows the roads and road name labels as depicted in the State Base Map.
• Structures:  This shows the Montana Structures and Addresses Framework.
• Transportation:  This shows roads, railroads, trails, and airports from the Montana Transportation Framework.
• Watershed Boundaries:  This shows the Hydrologic Units Framework.
• Wetlands/Riparian:  This shows the Montana Wetlands and Riparian Areas Framework.

Other Services

• Address Locator:  This service allows you to convert street addresses into geographic coordinates (i.e. Latitude/Longitude).
• State Mask:  This service may be used for covering map data that is not in selected states or provinces of North America or counties near Montana.
• State Base Map:  This service may be used as a general base map and has a map data overlay group for imagery services. The emphasis is on public and private land ownership data.  It also shows the Public Land Survey System, lakes and streams, roads, and landforms.
• Digital Orthophoto Quarter Quadrangle Data (DOQQ):  This is a mosaic of black and white orthorectified aerial photos of Montana and Yellowstone National Park taken predominantly in the 1990s. The mosaic footprint layer has an attribute field called Image_Year that gives the year the image was taken and a field called Image_Main_Date that gives the first date from the USGS metadata for the image.
• Historic Topographic Maps:  These 1:24,000 and 1:100,000 scale topographic maps were the newest scanned maps available from the U.S. Geological Survey TopoView web site as of November 2015. The data include the maps covering Montana and parts of Idaho and northern Wyoming. The data provides a historical reference and because they contain hand-placed elevation and place names the information may not be available on newer maps. Users should be aware that significant changes may have occurred in the landscape since the maps were made as many of the maps are over 30 years old.
• Flathead Basin 2009 Orthophotos and Elevation:  This shows high-resolution air photos, infrared air photos, and elevation data collected for the northern Flathead valley and the shorelines of Flathead Lake in 2009. A web map of this service is available for easier access to the data for users not using GIS software.
• Yellowstone River Hydrology:  This service shows data collected for the Yellowstone River Cumulative Effects Analysis, including the channel migration zone, historic locations of the river channel, man-made features that impact the flow of the river, and river miles. It also shows the river reaches designated for the analysis and aerial photos of the river made between 1948 and 1955.A web map of this service is available for easier access to the data for users not using GIS software.
• Reference100k:   This service provides a static base map of Montana designed to be viewed at a scale of approximately 1:100,000. Data shown on the map includes public land ownership, selected federal and state managed areas, lakes, streams, roads, the Public Land Survey system, 50-foot contours, shaded relief, and selected buildings and structures. A cached version is also available.