Sixteen miles below the confluence of the North Nahanni, but from the opposite or eastern side, Willow lake river enters the Mackenzie. It is a quarter of a mile wide, deep with a slack current. It is said to flow out of a lake of considerable extent, not far from the Mackenzie. Thirty-nine miles lower down, and three and a half miles above Fort Wrigley, a stream known to the Indians as “The River between Two Mountains” discharges into the Mackenzie from the east. It is about one hundred and fifty yards wide and shallow. Seventy-four miles below Fort Wrigley, on the west side, a river discharges a large volume of clear, black water, which rushes bodily half way across the Mackenzie, and preserves its distinctive character for several miles before it mingles with the main stream. The name applied to this river by the people at Fort Wrigley was “La Rivière le Vieux Grand Lac.” It is said to flow out of a lake of considerable extent lying not far from the Mackenzie. Many peaks can be seen up its valley. A little more than thirty miles lower down, on the same side of the river, another stream enters, apparently not more than a hundred yards wide at its mouth. Mr. Ogilvie saw it from the opposite side of the river only, and heard nothing concerning it. A small stream enters the Mackenzie opposite this place, and up its valley, about two miles eastward from the river, a sharp peak rising one thousand five hundred feet above the water was noted by Mr. Ogilvie. GRAVEL RIVER. Forty-one miles below the confluence of le Vieux Grand Lac river, or sixty-five miles, by the survey, above Fort Norman, a large river enters from the west. It is shallow at its mouth, as it is throughout its course, according to the reports of the Indians. The current, they say, is swift. They ascend it a long way in the winter to hunt, and descend in the spring on rafts. How far they go up, Mr. Ogilvie could not learn, their unit of distance being the unknown quantity of a day’s travel, but they go much farther than on any other tributary of the lower river. Mr. Ogilvie obtained the name from some Indians who had travelled it and they called it “Pecat-ah-zah.” This translated means Gravel river, by which name it is known to all the white men in the vicinity, on account of its shallowness and numerous gravel bars.