Many of these coureurs des bois became so accustomed to the Indian mode of living, and the perfect freedom of the wilderness, that they lost relish for civilization, and identified themselves with the savages among whom they dwelt, or could only be distinguished from them by superior licentiousness.  Their conduct and example gradually corrupted the natives, and impeded the works of the Catholic missionaries, who were at this time prosecuting their pious labors in the wilds of Canada.

To check these abuses, and to protect the fur trade from various irregularities practiced by these loose adventurers, an order was issued by the French government prohibiting all persons, on pain of death, from trading into the interior of the country without a license.

These licenses were granted in writing by the governor-general, and at first were given only to persons of respectability; to gentlemen of broken fortunes; to old officers of the army who had families to provide for; or to their widows.  Each license permitted the fitting out of two large canoes with merchandise for the lakes, and no more than twenty-five licenses were to be issued in one year.  By degrees, however, private licenses were also granted, and the number rapidly increased.  Those who did not choose to fit out the expeditions themselves, were permitted to sell them to the merchants; these employed the coureurs des bois, or rangers of the woods, to undertake the long voyages on shares, and thus the abuses of the old system were revived and continued.

The pious missionaries employed by the Roman Catholic Church to convert the Indians, did everything in their power to counteract the profligacy caused and propagated by these men in the heart of the wilderness.  The Catholic chapel might often be seen planted beside the trading house, and its spire surmounted by a cross, towering from the midst of an Indian village, on the banks of a river or a lake.  The missions had often a beneficial effect on the simple sons of the forest, but had little power over the renegades from civilization.

At length it was found necessary to establish fortified posts at the confluence of the rivers and the lakes for the protection of the trade, and the restraint of these profligates of the wilderness.  The most important of these was at Michilimackinac, situated at the strait of the same name, which connects Lakes Huron and Michigan.  It became the great interior mart and place of deposit, and some of the regular merchants who prosecuted the trade in person, under their licenses, formed establishments here.  This, too, was a rendezvous for the rangers of the woods, as well those who came up with goods from Montreal as those who returned with peltries from the interior.  Here new expeditions were fitted out and took their departure for Lake Michigan and the Mississippi; Lake Superior and the Northwest; and here the peltries brought in return were embarked for Montreal.