for the next twelve hours he described each of the islands he had found in lake michigan , the rapids above green bay , the courtesy and business acumen of the mascoutin , the surprises of the upper fox , the wild ride down the wisconsin , the first sighting of the mississippi , the meeting with the peorias , the hunting of buffalo , the many rivers that intersected the mississippi , including ones they thought might be helpful when traveling east or west , the arkansas and their threat , the illinois and their quick route to the lake of the illinois , and the huge lake that flowed into the lake of the hurons .