Missouri Headwaters State Park 
1585 Trident Road
Three Forks, MT 59752
406-994-4042
http://stateparks.mt.gov/missouri-headwaters/
State Park: Bike, Birding, Camp, Fish, Hike, Picnic, Walk, Water Sports
This park encompasses the confluence of the Jefferson, Madison and Gallatin Rivers. Lewis and Clark anticipated this important headwaters all the way up the Missouri River. An easy three-mile drive off Interstate 90 at Three Forks, this undeveloped park provides outdoor interpretive signs, picnic spots, short hiking trails, a small campground, and, just as the Corps of Discovery found, plenty of mosquitoes!