Mammoths, 

 Volcanos, 

 and Mountains 



The Aleutian Islands, Alaska, and the Yukon 



To the west of the great Canadian Lakes District there is a huge 

 peninsular province known as Alaska. As we are defining such 

 units, this comprises considerably more than the political state 

 known by that name, for it begins at the great mountain barrier 

 which slices down our continent just to the west of the Mackenzie 

 River, while its eastern periphery envelopes two-thirds of the 

 Canadian Yukon. 



Apart from the fact that this is a mountainous as opposed to a 

 more or less level plateau province, it differs very markedly 

 from the Northwest Territories and the central northern low- 

 lands of Canada. It has. around its northern and western pe- 

 riphery, a belt of truly Arctic tundra, appearing at first very like 

 that of the Keewatin Peninsula and even of the Islands, which 

 for most of the year is just flat, featureless, and usually col- 

 orless. It also slopes very gently to the shores of the Arctic 

 Ocean and the Bering Sea. This is a grim land, even when the 

 sun shines and its multitudinous dwarf plants are in flower. It 

 seems never to assume the vividness of color of the other central 

 and eastern tundras, and that coast which faces eastern Asia 

 over the narrow Bering Strait generally has a most dismal 

 aspect. 



It may surprise the uninitiated to find that this tundra belt 

 turns abruptly south and even southeast through Kodiak Island, 

 so that it comes to lie far south of even some part of the luxuri- 

 ant rain forests of the coast of the Gulf of Alaska. This would 

 appear to be "all wrong" had we not an over-all map showing 

 the continent-wide distribution of all the vegetational belts. The 

 reasons for these apparently somewhat erratic performances are 

 of course climatic: and these, in turn, are based primarily on the 

 major ocean currents. 



One of the most remarkable facts about the past history of 

 Alaska is that it does not seem to have been covered by an 

 icecap in recent geological times. When some two miles of ice 

 lay over the Canadian Lakes District and Hudson Bay. and even 

 when that icecap extended south to Missouri and Long Island, 

 this area (which is today a far northland) apparently remained 

 at least as free of snow as it is at present. There is even evidence 



Snow-covered Mounts Trident and Mageik of the Katmai 

 volcanic complex after a mild eruption. 



