Above the Mascoutin village, the Fox begins to narrow, being hemmed in, and often choked, by broad swamps of reeds and wild oats. The canoe traveler who does not know the channel, is sometimes in danger of missing it, and getting entangled in the maze of bayous. Two Miami guides were therefore obtained from their hosts, and on the 10th of June the travelers set off for the southwest, "in the sight of a great crowd, who could not wonder enough to see seven Frenchmen alone in two canoes, dare to undertake so strange and so hazardous an expedition." The guides safely conducted them to the place where is now situated the city of Portage, helped them over the swampy plain of a mile and a half in width, and, after seeing them embarked upon the broad waters of the Wisconsin River, left them "alone in an unknown country, in the hands of Providence." The broad valley of the Wisconsin presents a far different appearance from that of the peacefully flowing Upper Fox, with its outlying marshes of reeds, and its numerous lakes. The Wisconsin, or Meskousing, as Marquette writes it, is flanked by ranges of bold, heavily wooded bluffs, which are furrowed with romantic ravines, while the channel is, at low water, studded with islands and sand bars, and in times of flood spreads to a great width. Marquette himself describes it thus: "It is very broad, with a sandy bottom, forming many shallows, which render navigation very difficult. It is full of vine-clad islets. On the banks appear fertile lands diversified with wood, prairie, and hill. Here you find oaks, walnut, whitewood, and another kind of tree with branches armed with long thorns. We saw no small game or fish, but deer and moose in considerable numbers." About ninety miles below Portage, they thought that they discovered an iron mine. At last, on the 17th of June, they swiftly glided through the picturesque delta of the Wisconsin, near Prairie du Chien, and found themselves upon the Mississippi, grateful that after so long and tiresome a journey they had found the object of their search. Joliet's instructions were, however, to ascertain whether the great stream flowed into the "Southern Sea"; so they journeyed as far down as the mouth of the Arkansas. There they gathered information from the Indians which led them to believe that the river emptied into the Gulf of Mexico; thus the old riddle of the supposed waterway through the heart of the North American continent was left unsolved.