Missouri Headwaters State Park is a public recreation area occupying at the site of the official start of the Missouri River. The park offers camping, hiking trails, hunting, and water-related activities. It is located on Trident Road northeast of Three Forks, Montana at an elevation of . The park includes the Three Forks of the Missouri National Historic Landmark, designated in 1960 because the site is one where the Lewis and Clark Expedition camped in 1805. Setting The bulk of Missouri Headwaters State Park is found on a peninsula flanked on the east by the Gallatin River and the west by the Missouri River and the Madison River. Small parts of the park are also located on the east bank of the Gallatin River, and an island in the Missouri just below the confluence of the Madison and Jefferson Rivers. The total park size is . The Jefferson River meets the Madison and Missouri roughly midway through the park's north-south extent. History The Lewis and Clark Expedition encamped at the confluence site on July 26, 1805. On July 28, Meriwether Lewis wrote in his journal: "Both Capt. C. and myself in opinion with to the impropriety of calling either of these [three] streams the Missouri and accordingly agreed to name them after the President of the United States and the Secretaries of the Treasury and state..." The expedition were likely the first white men to ever penetrate this landscape. Lewis and Clark were at first uncertain how to proceed, and scouted each of the branches before ultimately departing on July 30 up the Jefferson River. The expedition also passed the forks on its return journey on July 13, 1806. As the west was explored and developed through the 19th century, the forks area was frequently used as a camp site by fur trappers. Acquisition for the state park was begun by preservation organizations in the 1960s. Claims of Missouri River source The Lewis and Clark decision not to call the Jefferson the Missouri has spurred debate over what is the longest river in North America, since the Missouri and Mississippi are nearly identical in length. The Missouri traditionally had been called the longest river in North America. However, 72 miles of it have been trimmed off in re-channeling its streambedmainly for the many hydroelectric power plants in the region so that it is now sometimes referred as second to the