ANIMAL LIFE ON THE SOURIS. 



299 



hours old, denoting the presence of Sioux or Assinniboines 

 in our neighbourhood. 



Before reaching the 49 th parallel, the Souris meanders 

 for several miles through a treeless valley, about a mile 

 broad and sixty feet below the prairie level. Turtle 

 Mountain on the east rises nobly from the great plain, 

 the boundary line between British and American ter- 

 ritory cutting it. The country west of the Souris is a 

 treeless desert, in dry seasons destitute of water, and 

 without a shrub or bush thicker than a willow twig. 

 We ascertained the breadth of this arid, woodless tract 

 to be at least sixty miles north of the Eed Deer's Head 

 Eiver on the 49th parallel. Near the boundary line the 

 Souris expands into a series of large ponds and marshes 

 which are called the Souris Lakes. During periods of 

 high water they form a continuous lake of imposing 

 magnitude, extending many miles south of the 49th 

 parallel, consequently far within the United States ter- 

 ritory. 



A vast number of gneissoid and limestone boulders are 

 strewed over the hill bank of the Souris, near the 49th 

 parallel, and on a point between a small brook and the 

 river we found a number of conical mounds, and the 

 remains of an intrenchment. Our half-breeds said it was 

 an old Mandan village ; the Indians of that tribe having 

 formerly hunted and lived in this part of the Great 

 Prairies. We endeavoured to make an opening into one 

 of the mounds, and penetrated six feet without finding 

 anything to indicate that the mounds were the remains 

 of Mandan lodges. There is a Mandan village near Fort 

 Clark on the Missouri, and in the country drained by 

 the Yellowstone the remains of this once numerous and 

 powerful tribe are now to be found. 



The mouth of Eed Deer's Head Eiver is within a few 



