7 6 The Shoshone Island. 



from lake to lake, till by progressive drain- 

 age the links grew into a continuous stream, 

 the Columbia river. 



It is with this lake period of the geolog- 

 ical history of Oregon that our narrative seeks 

 next to deal, and it is in its position sur- 

 rounded by these conditions that our Sho- 

 shone island develops the rest of its history. 

 As these surrounding lakes became smaller 

 and shallower the island extended, and these 

 extensions so varied its stretches of hill and 

 plain as to make it a region of exceptional 

 wealth of beauty and variety. 



That the climate was the climate of the 

 rhinoceros and the palm tree is proved by 

 the fact that the bones of the rhinoceros and 

 the leaves of the palm tree are now found in 

 the rocky sediments of its lakes. Sometimes, 

 too, one finds the fruit and leaves of an alder, 

 then those of a maple or an elm, often the 

 leaf or branchlets of a yew-like tree closely re- 

 sembling the California redwood. In fact 

 the leaves of the forest trees are large and 

 of wide range of species, impressing one with 



