As a state, Montana supports one of the smallest populations of interior least terns. Within Montana, least terns breed on sand and gravel bars along the Yellowstone River, below Miles City, and on the Missouri River, from below Fort Peck Reservoir to the Montana-North Dakota border. Reservoir shoreline at Fort Peck is also utilized in years when water and habitat conditions are suitable.
The interior population of the least tern (Sterna antillarum) is listed as endangered because of perceived low population size and threats to its breeding habitat. Alteration of natural river flow dynamics as well as recreational use of sandbar habitat has had a major impact on the reproductive success of the least tern. Consequently, breeding colonies in the interior U.S. are restricted to less altered river segments where there is still suitable habitat. [Learn more]