Missouri Headwaters State Park, State park and national historic landmark at Three Forks, Montana.

Missouri Headwaters State Park covers 535 acres on a peninsula flanked by the Gallatin River to the east and the Madison and Missouri rivers to the west. The Jefferson River joins the Madison roughly midway along the park's north-south extent, and an island lies in the Missouri just below that confluence. The park sits at 4,045 feet on Trident Road northeast of Three Forks.

The Lewis and Clark Expedition camped at the confluence on July 26, 1805, scouted each branch, and left on July 30 up the Jefferson River, returning past the forks on July 13, 1806. Lewis's journal of July 28 records the naming of the three streams after President Jefferson and the secretaries Gallatin and Madison. Fur trappers later used the forks as a campsite, and locals donated the first 8.5 acres in 1940; the park was created in 1947 and enlarged by over 200 hectares in the 1960s.

The three rivers meeting here received their current English names from the Lewis and Clark expedition, which named them after American statesmen. Locals come here to fish and picnic along the banks, where you can clearly watch the water flowing together from different directions.

The park remains open throughout the year, with campsites and trails suitable for day hikes. In summer, visitors can launch their own boats and paddle the rivers.

From the higher lookout point, you can see how the three rivers have slightly different shades before they blend together. The water line shifts noticeably with the seasons and mountain snowmelt.