Alaska is one of the only two states that are not bordered by another US state, Hawaii being the other. It is the only state that both is in North America and is not part of the 48 contiguous states; about 500 miles (800 km) of Canadian territory separate Alaska from Washington. Therefore, Alaska is an exclave of the United States that is part of the continental U.S. but is not part of the contiguous U.S. It is also the only mainland state whose capital city is accessible only via ship or air. There are no roads connecting Juneau to the rest of the state.

It is bordered by Yukon Territory and British Columbia, Canada to the east, the Gulf of Alaska and the Pacific Ocean to the south, the Bering Sea, Bering Strait, and Chukchi Sea to the west, and the Beaufort Sea and the Arctic Ocean to the north. Alaska is (by an extremely wide margin) the largest state by area in the United States. It is larger in area than all but 18 of the world’s nations.

Alaska is the largest state in the United States in terms of land area, 570,374 square miles (1,477,261 km²). In fact, it covers more than twice as much land than the next largest state, Texas. If a map of Alaska were superimposed upon a map of the Continental United States, Alaska would overlap Texas, Oklahoma, Kansas, New Mexico and Colorado, and if the state’s westernmost point was superimposed in San Francisco, California, its easternmost point would be in Jacksonville, Florida. Alaska also has the longest coastline of any state.

One scheme for describing the state’s geography is by labeling the regions:
South Central Alaska is the southern coastal region and is the population center for the state. The Municipality of Anchorage and many small but growing towns, such as Palmer, and Wasilla, lie within this area. Petroleum industrial plants, transportation, tourism, and two military bases form the core of the economy here.
The Alaska Panhandle, also known as Southeast Alaska, is home to Juneau, many small towns, tidewater glaciers and extensive forests. Tourism, fishing, forestry and state government anchor the economy.

The Alaska Interior is home to Fairbanks. The geography is marked by large braided rivers, such as the Yukon River and the Kuskokwim River, as well as Arctic tundra lands and shorelines. The Alaskan Bush is the remote, less crowded part of the state, encompassing 380 native villages and small towns such as Nome, Bethel, Kotzebue and, most famously, Barrow, the northernmost town in the United States.

The northeast corner of Alaska is covered by the Arctic National Wildlife Refuge, which covers 19,049,236 acres (79,318 km²). With its numerous islands, Alaska has nearly 34,000 miles (54,700 km) of tidal shoreline. The island chain extending west from the southern tip of the Alaska Peninsula is called the Aleutian Islands. Many active volcanoes are found in the Aleutians. For example, Unimak Island is home to Mount Shishaldin, a moderately active volcano that rises to 9,980 ft (3,042 m) above sea level. The chain of volcanoes extends to Mount Spurr, west of Anchorage on the mainland.

North America’s second largest tides occur in Turnagain Arm just south of Anchorage, which often sees tidal differences of more than 35 feet (10.7 m). Alaska is home to 3.5 million lakes of 20 acres (8 ha) or larger. Marshlands and wetland permafrost cover 188,320 square miles (487,747 km², mostly in northern, western and southwest flatlands. Frozen water, in the form of glacier ice, covers some 16,000 square miles (41,440 km²) of land and 1,200 square miles (3,108 km²) of tidal zone. The Bering Glacier complex near the southeastern border with Yukon, Canada, covers 2,250 square miles (5,827 km²) alone.

The Aleutian Islands actually cross longitude 180°, technically making Alaska the easternmost state as well as the westernmost - but nobody thinks of it that way because meridians of longitude are artificial lines drawn upon maps, whereas the peninsula that is Alaska and the Aleutian Islands that extend westward from it are physically and undeniably the westernmost points of North America. Alaska and, especially, the Aleutians are one of the extreme points of the United States. The International Date Line jogs west of 180° to keep the whole state, and thus the entire continental United States, within the same legal day.

According to the October 1998 report of the United States Bureau of Land Management, approximately 65% of Alaska is owned and managed by the U.S. Federal Government as national forests, national parks, and national wildlife refuges. Of these, the Bureau of Land Management manages 87 million acres (350,000 km²), or 23.8% of the state. The Arctic National Wildlife Refuge is managed by the United States Fish and Wildlife Service.

Of the remaining land area, the State of Alaska owns 24.5%; another 10% is managed by thirteen regional and dozens of local Native corporations created under the Alaska Native Claims Settlement Act. Various private interests own the remaining land, totaling less than 1%.

Alaska is administratively divided into “boroughs,” as opposed to “counties.” The function is the same, but whereas most states use a three-tiered system of decentralisation - state/county/township - Alaska only uses two tiers - state/borough. Owing to the state’s low population density, most of the land is located in the Unorganized Borough which, as the name implies, has no intermediate borough government of its own, but is administered directly by the state government.

For purposes of the federal census, the state is also divided into a number of artificial divisions defined geographically by the United States Census Bureau for statistical purposes only. For a list of boroughs and census areas in Alaska, see List of boroughs and census areas in Alaska.