North West Co. fort on left bank of Souris river near mouth Plum Creek, a tributary of Souris river. Was located 16&fract12; miles south and 39 miles west of McDonnell's House, probably near or opposite the present village of [Souris], Manitoba. It was an outpost of Assiniboine House about 45 miles distant. Built 1795 and abandoned 1796. Thompson Journal December 1797 says, "had to be given up from its being too open to incursions of Sioux Indians". In July 1806 Alexander Henry Jr. visited the site of Ash House on his journey to the Mandan Indians. Was on the direct route to the Mandan villages. It was known also as Fort de la Frenier (Ash tree).