The arrival of the _Griffin_ brought Indians by the hundred to marvel at the "floating fort" and to barter their furs for the trinkets with which La Salle had provided himself. The little vessel then sailed westward into Lake Michigan and finally dropped anchor in Green Bay where an additional load of beaver skins was put on deck. With the approach of autumn the return trip began. La Salle, however, did not accompany his valuable cargo, having a mind to spend the winter in. explorations along the Illinois. In September, with many misgivings, he watched the _Griffin_ set sail in charge of a pilot. Then, with the rest of his followers he started southward along the Wisconsin shore. Reaching the mouth of the St. Joseph, he struck into the interior to the upper Kankakee. This stream the voyageurs, who numbered about forty in all, descended until they reached the Illinois, which they followed to the point where Peoria now stands. Here La Salle's troubles began in abundance. The Indians endeavored to dissuade him from leading the expedition farther, and even the explorer's own followers began to desert. Chagrinned at these untoward circumstances and on his guard lest the Indians prove openly hostile, La Salle proceeded to secure his position by the erection of a fort to which he gave the name Crèvecoeur. Here he left Tonty with the majority of the party, while he himself started with five men back to Niagara. His object was in part to get supplies for building a vessel at Fort Crèvecoeur, and in part to learn what had become of the _Griffin_, for since that vessel had sailed homeward he had heard no word from her crew. Proceeding across what is now southern Michigan, La Salle emerged on the shores of the Detroit River. From this point he pushed across the neck of land to Lake Erie, where he built a canoe which brought him to Niagara at Eastertide, 1680. His fears for the fate of the _Griffin_ were now confirmed: the vessel had been lost, and with her a fortune in furs. Nothing daunted, however, La Salle hurried on to Fort Frontenac and thence with such speed to Montreal that he accomplished the trip from the Illinois to the Ottawa in less than three months--a feat hitherto unsurpassed in the annals of American exploration.