Historic Aerial Photography includes aerial photographs and aerial photo mosaics from which other baseline datasets, such as banklines and flowlines are extracted. The historic bankline and flowline datasets are then used to develop indicators of change within the Yellowstone River stream corridor. They are a foundational element of the Yellowstone River Cumulative Effects Assessment because they allow detection of change within the stream corridor over the last 55+ years.
Floodplain Analysis Products are a by-product of the Yellowstone River Cumulative Effects Assessment. They provide information about historic channel change and risk of flooding and erosion within the Yellowstone River corridor. They should be considered as an initial point of reference for more detailed project- or site-specific studies. Their development was sponsored by Yellowstone River Conservation District Council to inform land use decisions within the Yellowstone River floodplain.
Hydraulic Analysis Results - Flood modeling has produced estimated inundation areas and depths for the developed conditions and hypothetical pristine conditions of the Yellowstone floodplain for 2-year, 5-year, and 100-year events for every county below Springdale and for 10-year, 20-year, 50-year, 200-year, and 500-year events for selected counties.
Bank and Flowline GIS Data download for 1950 (entire length of river corridor, MT), 1976 (Sweet Grass County to confluence with Missourri River), 1995 (Sweet Grass County to confluence with Missourri River), 2001 (entire length of river corridor, MT). and 2015 (Reed Point to Custer, MT) – ESRI personal geodatabase format.
Geomorphic Reconnaissance and GIS Development (2004)- This page has links to a collection of GIS layers developed for the river corridor in 2004. The collection includes historical Government Land Office Maps, maps of proposed data collection areas, proposed river reach boundaries, the valley bottom centerline, and several base map layers derived from larger data collections that are available elsewhere. View page listing available reconnaissance GIS layers
Land Use Mapping and Analysis- This data consists of land use polygons digitized from 1948-1950's, 1976-1977, 1999-2001, and 2012 aerial orthophotographs. Download land use data in geodatabase format.
National Wetlands Inventory - These are geodatabases containing the National Wetlands Inventory for Montana, provided by the Montana Natural Heritage Program. Data for the Yellowstone River Corridor region was added to the National Wetlands Inventory (NWI) in 2010. Montana wetland and riparian mapping data in geodatabase format are available here.
Physical Feature Inventories document the development of flood and erosion control structures over time within the Yellowstone River Corridor, and also contain features such as diversion structures and irrigation return flow points.
2015 Inventory download. This is the 2011 inventory with updates for Reed Point to Custer only, based on high-resolution 2015 aerial photos.
2011 Inventory download - This is a revision of the 1999-2001 inventories, based on high-resolution 2011 aerial photos
1999-2001 Inventory downoad - This is a combination of an inventory of the river done from 1999 aerial photos of Park County and a field inventory of the remaining counties performed in 2001.
Planimetric Feature Data - These data show locations of roads, streams, ponds, spot elevations, buildings, and other structures digitized from aerial photographs taken in 2004 and 2007, and elevation contour lines derived from the LiDAR data. ESRI geodatabases by county are available here.
Russian Olive Inventory - Produced by the Natural Resources Conservation Service, this GIS shapefile documents the distribution and extent of Russian Olive along the Yellowstone River main stem and major tributaries for purposes of education and control. The data were extracted from 2009 true color aerial photographs developed by the National Agricultural Imagery Program (NAIP) using ArcGIS 9.2 and the Feature Analyst extension. It includes approximately 500,000 individually attributed polygons. Download in Shapefile format.
Study Reaches are 89 segments of the river valley that are described in the Cumulative Effects Analysis and were delineated based on river form/pattern and the level of confinement of the stream. Download in shapefile format