Ronan is a city in Lake County, Montana, United States. It lies on the Flathead Indian Reservation about 12 miles south of Flathead Lake in the northwestern part of the state. The population was 1,812 at the 2000 census.According to the United States Census Bureau, the city has a total area of 1.1 square miles (2.8Square Kilometer), all of it land. It serves as the hub of the agricultural community in the Mission Valley. Adorned with the beauty of the Mission Mountains and various sources of fishing and wildlife habitat, the community of more than 3,000 residents offers a variety of opportunities.