The first humans in the Western Hemisphere are believed to have come from Asia across the Beringian land bridge into Alaska 12,000–15,000 years ago. The first to arrive were the Paleoindians, who spread throughout North America and South America and from whom most native American cultures derived, including the Haida and Tlingit Indians of the southeastern coast of Alaska (Greenberg 1987). Later migrations of people are believed responsible for the Athabascan Indian cultures that are present throughout the interior and south-central regions of Alaska and in parts of northwestern Canada. The marine-oriented Eskimos of Arctic, western, and southwestern Alaska (represented today by the Inupiat, Yup'ik, and Koniak cultures) arrived much later, apparently by boat across Bering Strait. The Aleut culture of the Aleutian Islands and adjacent Alaska Peninsula has its closest affinity to early Eskimo cultures.

Today, the human population of Alaska is about 610,000, with the majority concentrated in and around Anchorage, Fairbanks, Juneau, and smaller southcoastal cities of a few thousand each. The Alaskan population is younger than the rest of the United States (median age 30 years versus 33.4 years for the whole United States), and its rate of population increase in recent years is second only to that of Nevada (Alaska Bureau of Vital Statistics 1995). The nonindigenous residents of Alaska (those who are not Alaska Natives of Eskimo, Indian, or Aleut descent as defined by the Alaska Native Claims Settlement Act of 1971) make up about 84% of the Alaskan population, and about 80% of them live in urban communities. The non-Native residents of Alaska are primarily first-or second-generation immigrants from the other states and reflect the racial and ethnic diversity that characterizes the United States. There are some differences in the racial make-up between Alaska and the United States as a whole. Alaska's population is 4.1% black (12.1% for the entire United States), 16% Native American (0.8%), and 3.2% Hispanic of any race (9%), according to the 1990 US census. Alaska Natives currently make up 16.5% of the state's population and most live in rural communities (Wolfe 1996). There are about 225 rural communities of fewer than 500 residents scattered throughout the state but concentrated in southeastern Alaska. The residents of all but a few of those communities are predominantly Alaska Natives.

Human activities have had less effect on the ecosystems of Alaska than elsewhere in the United States. Conversion of land to agricultural use has been minimal, as is the extent of land alteration through mining and petroleum development. The greatest alteration of ecosystems has been through extensive logging of forests in southeastern Alaska. More than 40% of Alaska is managed by federal agencies through the National Park Service, Fish and Wildlife Service, and Bureau of Land Management.