Lolo is a census-designated place (CDP) in Missoula County, Montana, United States. It is part of the Missoula Metropolitan Statistical Area. The population was 3,892 at the 2010 census, an increase from its population of 3,388 in 2000. It is home to Travelers' Rest State Park, a site where Lewis and Clark camped in 1805 and again in 1806.