Darkness fell as we reached an elevation overlooking the river above the Naiwa Rapids, and after some deliberation as to the spot where we should suffer less annoyance from mosquitos, I proceeded to the lower part of the valley near the river, and set up my tent there for the night. On questioning Ozawindib of the Naiwa River, he informed me that it was a stream of considerable size, and that it originated in a lake on a distant part of the plateau, which was infested with the copper-head snake; hence the name. Mr. Allen's estimate of this day's journey was fifty-two miles. We had reached the second, or Assawa plateau of the Mississippi, which is, barometrically, seventy-six feet above the Queen Anne summit, and now had but one more to surmount. CHAPTER XXIII. The Expedition having reached the source of the east fork in Assawa Lake, crosses the highlands of the Hauteurs de Terre to the source of the main or west fork in Itasca Lake. The next morning (13th) a dense fog prevailed. We had found the atmosphere warm, but charged with water and vapors, which frequently condensed into showers. The evenings and nights were, however, cool, at the precise time of the earth hiding the sun's disk. It was five o'clock before we could discern objects with sufficient distinctness to venture to embark. We found the channel of the river strikingly diminished on getting above the Naiwa. Its width is that of a mere brook, running in a valley half a mile wide. The water is still and pond-like, the margin being encroached on by aquatic plants. It presents some areas of the zizania palustris, and appeared to be the favorite resort for several species of duck, who were continually disturbed by our progress. After diligently ascending an hour and a half, or about eight miles, the stream almost imperceptibly began to open into a lake, which the Indians called Assawa, or Perch Lake. Its borders are fringed with the _monomin_ of the Chippewas, or wild rice, and several of the liliaceous water plants. The water is transparent when dipped up and viewed by the light, but from the falling of leaves and other carbonaceous fibre to the bottom, it reflects a sombre hue. We were just twenty minutes in passing through it, denoting a length of perhaps two miles, and a width of half a mile. Our course through it was directly south. Ozawindib, who took the advance, entered an inlet, but had not ascended it far, when he rested on his paddles, and exclaimed _o-omah mekunnah_, here is the path, or portage. We had, in fact, traced this branch of the river into its utmost sources. It was seven o'clock in the morning. We were surrounded by what the natives term _azhiskee_, or mire, broad-leaved plants extending over the surface of the water, in which I recognized a diminutive species of yellow pond-lily. There was no mode of reaching dry land but by stepping into this yielding azhiskee. The water was rather tepid. After wading about fifty yards the footing became more