Fort Union National Historic Site Professional Review and Guide
"Although the actual location of old Fort Union is in present-day North Dakota 500 feet east of the Montana line, it was once a part of the original Montana Territory and played a significant role in the exploration of Montana. Lewis and Clark passed by here in 1805 and 1806, well before the fort was established in 1829. Fort Union, built near the banks of the Missouri River and close to the confluence of the Yellowstone River, was an important frontier trading post for beaver furs and bison hides until 1866.
Indians, trappers, traders, artists, priests, explorers, and scientists visited Fort Union. Such famous people as George Catlin, Prince Maximilian, Karl Bodmer, Father DeSmet, Jim Bridger, Jedediah Smith, and John James Audubon visited the fort. Today’s Fort Union National Historic Site is a partial reconstruction on the original site, and is a fascinating place to visit, where a walk over the state line from the parking lot to the fort will put you in a different time zone (Mountain Standard Time-Central Standard Time). This eTrail provides detailed information on birding strategies for this specific location, the specialty birds and other key birds you might see, directions to each birding spot, and helpful general information."