36 BOTANY OF THE ROUTE. 



The Columbia continues fresh so near its mouth that I have found the water drinkable even 

 at high tide, and in August, just within Cape Disappointment, less than a mile from the 

 breakers outside the bar. 



To this fact is attributable the scarcity of such animals as usually inhabit estuaries. Though 

 I visited the place at all seasons I never found on the shores of Baker's bay but two species of 

 mollusca, while in Shoalwater bay, only a mile or two north of it, are more than twentj'. But 

 several species are known to inhabit the deep water about the bar of the Columbia, where they 

 were dredged up by the Exploring Expedition. It is probable that the water is much salter at 

 that depth than near the surface. 



Aquatic mammalia, such as beaver, muskrat, otter, and seal, abound in the fresh waters; 

 and one seems to be peculiar to the Territory, the water shrew, (Neosoeex navigator,) caught 

 while swimming a foot below the surface of one of the lakes at the head of the Yakima river, 

 and at least 2,500 feet above the ocean. 



SALT WATERS OF THE TERRITORY. 



The salt waters of the Territory constitute a botanical and zoological region, equal in 

 importance to the others described, and, in their great variety of animal life, far surpass the 

 corresponding portions of the Atlantic coast. A short description of the peculiarities in the 

 conformation of the shores will, in some degree, account for this fact. Commencing with the 

 northwest sounds, we find there a large body of water from twenty to sixty fathoms deep, with 

 shores almost everywhere bold and hard, so that the largest ships can literally tie fast to the 

 trees along shore in many portions where they cannot readily anchor on account of the depth. 

 This great body of water is nearly as salt as the ocean itself, and is renewed twice in each day 

 by tides, which range between the limits of eighteen feet, each alternate tide being less than 

 the preceding, until it is reduced to a rise or fall of less than a foot, when it begins to 

 increase again, the other series decreasing in its turn. By this arrangement it happens that 

 the extreme low tides occur about once in every fortnight. 



The high mountains, and generally steep cliffs on each side, completely protect the sounds 

 from storms, so that calms are almost constant in their inner labyrinths, and they are thus aa 

 admirably fitted for the production of animal life as the most carefully constructed aquarium. 

 In very short visits and hasty voyages on the sounds I had little opportunity for collecting, and 

 obtained, I believe, nothing new. But the great number of animals obtained by others, and 

 most of which exist in abundance, show its richness in zoology, while it may be safely estimated 

 that a third of its inhabitants are yet unknown to science. 



A long residence at Shoalwater bay allows me to speak of it more particularly. It is 

 twenty-five miles long and from three to seven wide, thus including an area of more than a 

 hundred square miles. Of this large surface two-thirds may be said to become bare at ordinary 

 low tide, and probably more than three-quarters at the lowest semi-monthly ebbs, of which 

 those of May and June are even lower than the others, though all less in their extremes than 

 those of the sounds. 



The least depth of water on the bar is, by the Coast Survey charts, three and a quarter 

 •fathoms, which increases just within it to seventeen fathoms, and varies in the channels from 

 this depth to three fathoms at the mouths of the larger rivers. There are five rivers emptying 

 into the bay, which bring down a large amount of fresh water, and six large creeks, which, 

 .though wide at high water, become almost dry at medium ebb-tides, and were caused by the' 



