1908.] ROUTES TRAVERSED MACKENZIE. 103 



dwarfed state on the extreme summit. Other plants of interest are 

 mountain avens (Dryas integrifolia and drummondii), Pedici/laris 

 euphrasioides, Pinguicula vulgaris, and Anemone richardsoni. 



From the summit of Mount Tha-on'-tha (see PL XII). which 

 I ascended on June 4. 1904, an interesting prospect presented itself. 

 Ten or 15 miles to the westward Mount Camsell (PL XI, fig. 1), 

 on whose barren summit much snow vet remained, loomed up to a 

 height of about 4,000 feet, or over a thousand feet higher than the 

 peak on which I stood, and beyond other still higher peaks could be 

 seen. To the north and northwest extended lofty rugged mountains, 

 the highest capped with snow. Farther back it is impossible to see 

 whether or not the mountains are arranged in definite series, but the 

 most easterly ranges are very well marked and lie parallel to the 

 Mackenzie. To the eastward, beyond the broad river, stretches a vast 

 rolling plain, well forested and dotted here and there with lakes. 

 To the south is a low, level, wooded plain, with thousands of small 

 lakes. 1 (ordered on the west by the Xahanni Mountains and the 

 low foothills back of Fort Simpson. Between the Mount Camsell 

 range and the mountains to the northward lies the deep valley of the 

 North Xahanni River, with its broad, muddy flood plain, through 

 which the river, spread out in numerous channels, pursues its mean- 

 dering course. 



Below the mouth of the Xahanni River (PI. XII, fig. 2) die Mac- 

 kenzie makes its abrupt turn above referred to, and for some miles 

 parallels closely the Xahanni Mountains. A number of long, narrow 

 islands, closely wooded with spruces, lie close to the western bank. 

 The largest of these is about 20 miles long. Root River enters the 

 Mackenzie from the west 10 miles below the Xahanni. and 4 miles 

 below, opposite the lower part of Twentymile Island, Willow Lake 

 River comes in from the east, both being small streams. Here the 

 high mountains have receded from view, and the sides of the valley 

 are only moderately elevated. Twenty-live miles below a slight rapid 

 occurs, inclosing an island, and here on the right bank, at the time of 

 our visit, stood Fort Wrigley. (See PI. XIII, fig. 2.) It is a small 

 and unimportant post and may l»e passed by without further comment. 

 Below here the Mackenzie pursues a general northerly course, with 

 rather high banks on the right. Twenty-five miles below the Little 

 Rapid the "Rock by the Riverside.' or Roche Trempe-l'eau (fig. 6), 

 as it is generally called, forms a part of the right bank. It i^ an 

 uplift of Devonian limestone, rising directly from the water to a 

 height of 1.500 feet. Below this point the left hank' becomes higher 



" Fori Wrigley was established in 1877, and was al lirst known as 'The 

 Little Rapid.' Its she proved i<> be unhealthy and lately (autumn, 1904) it 

 has been abandoned and the post reestablished 25 miles lower down, on the left 

 hank opposite Roche Trempe-l'eau. 



