Roadside turnout with historical marker sign South side of highway. The Judith River. The Lewis and Clark expedition came up the Missouri River in 1805 Capt. Clark named the Judith River for one of the girls he left behind him. Montana, from skiing to, sailing to snowmobiling, wildlife watching to golfing, fishing to hiking, whitewater rafting to just relaxing and taking in the scenery, there are a plethora of activities to keep you busy as long as you care to stay.