He follows the army to Fort Frontenac and Niagara where the troops build a fort which is put under the command of the chevalier Pierre de Troyes. Although he had planned on returning to France, the Baron agrees to stay. He leaves Fort Frontenac on August 3 with Dulhut and about a hundred men. They then cross Lake Erie, go up the Detroit River to Lake Saint Clair which they reach on September 8. Six days later, they arrive at Fort Saint-Joseph, at the entrance to Lake Huron.
Winter is hard for the detachment.
It is short of supplies and is worried about an attack by the Iroquois. Later that same spring, he travels as far as the rapids at Sainte-Marie, where they enter Lake Superior. The commander and his soldiers leave for Michillimakinac that same day. South of the bay, he canoes down Fox River and portages to the Wisconsin River. Once there, he continues to head west until he reaches the Mississippi River.