Pierre Gaultier de Varennes, sieur de La Vérendrye, the son of Rene Gaultier, Sieur de Varennes, the longtime governor of Trois Rivieres, had become in 1726 the partner of his brother Jacques Rene in the fur trade north of Lake Superior, where he has net Amerinds whose tales persuade him that a water route through the lakes and rivers of the northwest leads to the storied Western Sea.

Vérendrye, an ex-soldier, had farmed and fur traded to support his family until 1727 when he moved to Nipigon to command that fort.

He had in 1728 been appointed commandant of the French posts on the north shore of Lake Superior, and in in 1731 begins his explorations in earnest.

One of the main objectives is to find a route to the Western Sea.

The governor and intendant of New France backs Vérendrye, accompanied by three of his sons and a nephew, in establishing a post at Rainy Lake, the first of several such posts along an intended route toward the western ocean.