A settlement started in 1853 by Louis Raboin, a French-Canadian who married a Flathead Indian. He was small and lively and local Native Americans nicknamed him Maringouin, a French slang term for mosquito. Later the name was twisted to Marengo and given to the settlement. A score of buildings were centered around a gas station, a schoolhouse, and a general store. In 1877, the Grange erected a flour mill here, and a post office was established the following year. In Marengo is a junction with Tucannon Rd.; a left on this road routes you through picturesque Tucannon Canyon. High, rocky walls hem in the narrow valley, broken here and there by scattered brush or an occasional clump of cottonwoods. Fishing was good and Chinese pheasants, quail, and partridge were plentiful.