﻿1848. ELK OR ATHABASCA RIVER. 127 



In no place did I observe the limestone alter- 

 nating with these sandy bituminous beds, but in 

 several localities it is itself highly bituminous, 

 contains shells filled with that mineral, and when 

 struck yields the odour of Stinkstein. It is pro- 

 bable that the whole belongs to the same forma- 

 tion, but I do not possess evidence of the facts to 

 satisfy a geologist. 



The rate of our descent of the Elk River must 

 this day have exceeded six geographical miles an 

 hour, indicating a strong current. This river, 

 named also the Athabasca or Riviere la Biche^ 

 rises in the parallel of 47^° north latitude, near 

 the foot of Mount Brown, a peak of the Rocky 

 Mountains, having a height of sixteen thousand 

 feet above the sea. Its course in a straight line to 

 the influx of Clear-water River is three hundred 

 miles ; but the river course, including its windings, 

 must be more than one third greater. The ele- 

 vation of its sources is probably seven or eight 

 thousand feet. Lesser Slave Lake, situated about 

 midway between its origin and the junction above 

 mentioned, lies, according to Captain Lefroy, 

 eighteen hundred feet above the sea. Some of the 

 feeders of the Oregon spring from very near the head 

 of the Athabasca, and many tributaries of the Saskat- 

 chewan arise not far to the southward. It is the 

 most southern branch of the Mackenzie ; and as it 



