Description: State Seal of Montana — with the Great Falls of the Missouri River.
Credit: ATSDR (part of the CDC) series of state-specific fact sheets. Bitmap versions have been seen on US Embassy websites. Direct PDF URL 
Author: U.S. Government
Permission: U.S. Government rendition; copyright is owned by the artist (not necessarily the states), which in this case is the federal government.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No