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This layer shows the outlines of the states of the United States and the nations of North America. The data were downloaded from Natural Earth. The boundary of Montana was replaced with the Montana Spatial Data Infrastructure representation of the boundary and other boundaries that approach Montana were edited to be more correct. The data were converted from polygons to linear boundaries at the Montana State Library and the attributes with names of the adjoining nations and regions (state or province equivalents) were assigned, along with a field to differentiate coastlines, national boundaries, and US state boundaries from state or province equivalent boundaries in other nations. The Natural Earth data were not topologically correct. To create a single line for each boundary the polygons were brought into an ArcGIS topology which automatically corrected all lines that were within 5 meters of each other. The remaining gaps and overlaps were corrected by hand. The boundaries were created from the polygons with the ArcGIS Polygon to Line tool. |