On his arrival in Quebec, in order that he learn their language, he was sent to live with the Algonquins on Allumette Island, a friendly First Nation settlement on the important fur trade route on the Ottawa River. Nicolet returned to Quebec in 1635, but was then directed to go to the Lake Nipissing area where he spent more than eight years among the Nipissing First Nation nation, running a store and trading with the various indigenous peoples in the area.
From a relationship with a Nipissing native, a woman named Marie Savage, he had a daughter, Madeleine Euphrosine Nicolet, whom he later brought back with him to the colony. On July 19, 1629, when Quebec fell to the Kirke brothers who took control for England, Jean Nicolet fled back into the safety of the Huron country and worked against English interests until the French were restored to power.
Jean Nicolet is noted for being the first European to cross Lake Michigan, and, in 1634, became Wisconsin's first European explorer. He landed at Red Banks, near modern-day Green Bay, Wisconsin, in search of a passage to the Orient. He and others had learned that the people who lived along these shores were called Winnebago ("the people from the stinking water") and "the People of the Sea." He concluded that these people must be from or near the Pacific Ocean and would provide a direct contact with China.