The Alaska Interior covers most of the U.S. state’s territory. It is largely wilderness. Mountains include Mount McKinley in the Alaska Range, the Wrangell Mountains, and the Ray Mountains. Interior Alaska experiences extreme seasonal temperature variability. Winter temperatures in Fairbanks average −12 °F (−24 °C) and summer temperatures average +62 °F (+17 °C).
Fairbanks is the largest city in the Interior region of Alaska, and second largest in the state, after Anchorage. It is the northernmost Metropolitan Statistical Area in the United States, lying less than 120 miles (190 km) south of the Arctic Circle. Fairbanks is located in the central Tanana Valley, straddling the Chena River near its confluence with the Tanana River.
Yukon is the westernmost and smallest of Canada’s three federal territories. Whitehorse is the territorial capital. The territory was split from the Northwest Territories in 1898. At 5,959 m (19,551 ft), Yukon’s Mount Logan, in Kluane National Park and Reserve, is the highest mountain in Canada and the second-highest on the North American continent (after Denali in the U.S. state of Alaska). Several rivers run through Yukon, some being the Stewart River, Peel River, and ever famous Yukon River.
Whitehorse is the capital and largest city of Yukon and the largest city in northern Canada. It was incorporated in 1950 and is located at kilometre 1426 on the Alaska Highway in southern Yukon. Whitehorse’s downtown and Riverdale areas occupy both shores of the Yukon River, which originates in British Columbia and meets the Bering Sea in Alaska. The city was named after the White Horse Rapids for their resemblance to the mane of a white horse, near Miles Canyon, before the river was dammed. Because of the city’s location in the Whitehorse valley, the climate is milder than other comparable northern communities. The town of Whitehorse, as reported by the Guinness World Records, is the city with the least air pollution in the world.