Flying Post was a Hudson's Bay Company trading post located on the Kukatush (variously spelled Kuckatoosh or Ahkuckootish) or Groundhog River, a tributary of the Mattagami River. The post was approximately eighty miles downriver from Kukatush or Groundhog Lake, and one hundred miles upriver from the river's junction with the Mattagami. It was approximately fifty miles northwest of Matawagamingue.