Originally a King's post in Domaine du Roy, on river Ashuapmuchouan about 10 miles above the mouth, on the shore of lake Chigobiche an enlargement of the river. Built 1690. Was on route from lake St. John to James Bay as travelled by Father Albanel 1672. Was operated by French up to time of cession 1760. Leased by North West Co. with other King's posts 1788. James McKenzie of North West Co. visited the King's posts 1808 and says in his description of this post: "It is 60 leagues from lake St. John on a small lake of the same name. A poor shabby post. There is a route from hence to river St. Maurice by small lakes and rivers". It is shown on Laure's map 1732 and Bowen and Gibson's map 1772 (White). In 1825 it was operated by King's Posts Co. In 1831 the Hudson's Bay Co. acquired lease of this and other King's posts. It is shown on Arrowsmith map 1848. Was closed before 1871. The name means "Watch Moose Deer" and is variously spelled Assuapmousoin, Chamuchuan, and Chamouthouane. Shown on White's Map of Labrador posts (No. 24) and La Rouge 1755 (No.112) & Bellin 1744 (No. 95).