Fort Aux Cedres took its name from Cedar Island. The island was in the Missouri River just above the Big Bend. It was about thirty-five miles southeast of Fort Pierre. The island was covered with cedar trees. Registre, or Regis, Loisel built the fur post of red cedar logs. Loisel was a Frenchman from Canada who worked for a Saint Louis fur company. He did a good business with the Lakotas. Fort Aux Cedres burned down in 1810.