9781422286135

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Non-Continental: Alaska, Hawaii

Kuskokwim, Tanana, and Yukon River valleys. The Rocky Mountain System is north of the Central Uplands and Lowlands and includes the Brooks Range and the Brooks Range foothills. The Brooks Range was formed by gla- ciers and includes peaks that rise 9,000 feet (2,700 m) above sea level. The Arctic Coastal Plain covers the northernmost portion of Alaska and is a treeless plain that slopes toward the Arctic Ocean. The area features a per- manently frozen ground known as per- mafrost . In the spring, some areas defrost enough to allow grass and wildflowers to grow. This area is called the tundra. The Yukon River runs from Atlin Lake in British Columbia through Canada’s Yukon Territory and throughout central Alaska, traveling from east to west. At 1,980 miles (3,187 km), the Yukon, which is believed to come from the Indian word for “big river,” is the longest river in North America. The second longest river in Alaska is the Kuskokwim River, which runs

Did You Know?

In Barrow, the sun sets in November and does not rise again until the mid- dle of January.

for 702 miles (1,130 km). The river’s headwaters are in the Kuskokwim Mountains and the Alaska Range. It runs to Kuskokwim Bay on the Bering Sea bordering western Alaska. The river’s name is believed to be a loose translation from the Yupik word for “big, slow-moving thing.” Other notable Alaskan rivers include the Colville River, which begins in the De Long Mountains above the article circle. Frozen for more than six months a year, the river is used as a highway in the winter. The Copper River is 300 miles (483 km) long and is named for the copper deposits found along its banks in the upper regions of the river. The river features an extensive delta and is also known for the more than two mil- lion wild salmon that spawn upstream