Although the characters of Alaska live in times as vast and as varied as the Alaskan terrain (some are not even human), most share one common trait: They have journeyed to and been captured by the Alaskan "Ice Castle." In many cases, this captivity is literal as well as metaphorical, for Michener's first wanderers are those who cross the Bering Strait from Asia to Alaska during the Earth's several ice ages, and they (or their descendants) are trapped when rising waters cover the land bridge during an interglacial period.

Animal characters, like human ones, encompass both prehistoric and historic times. These include Mastodon, who 385,000 years ago led his cows into Alaska, searching for a more plentiful food source; and valiant Matriarch, whose wiles protect her woolly mammoth herd from fire, but not from the danger of Alaska's first human inhabitants. Perhaps the most interesting of these animal characters is Nerka, the sockeye salmon, whose entire life span, as well as twentieth-century man's systematic decimation of his species, is graphically described.

Michener quickly establishes his major themes through the characters in "The People of the North." The exodus from Asia begins almost 29,000 years ago, when Varnak and his people walk across the Bering Strait. Like many nomads who precede and follow them, Varnak and his people have no knowledge that they have journeyed from one continent to another; they know only that they must follow the mammoth or die. Varnak kills the daughter of the mammoth Matriarch so that his people will survive, but this death allows Michener to establish a pattern which can be seen throughout the novel: Alaskans (both men and animals) who are weak, innocent, and peaceful are soon displaced by those who are strong, hungry, and violent.

In 14,000 B.P.E. during an interglacial period, Varnak and his people are joined by another group of Asian hunters who will someday be known as Eskimos. Although these Siberian seafarers are basically a peaceful people, their livelihood depends upon the courage and skill required to hunt whales in the Arctic Ocean. Therefore, the cross-eyed, awkward hunter Oogruk seems unheroic in the eyes of his people. Yet, Oogruk's wife Nukleet, daughter of the chief of the village, appreciates him for his integrity and compassion, traits which many better hunters do not have. The shaman of Oogruk's village, who uses his position to force himself on pretty Nukleet and overthrow her father's rule, is the catalyst which forces Oogruk to leave Asia. Incapable of fighting the shaman's power, Oogruk, Nukleet, her father, and her young daughter brave the icy Bering Sea in a small kayak to begin a new life in Alaska.

Two thousand years later, the people whom later cultures will name the Aleuts begin a trek of their own. Pushed out of Asia and mainland Alaska by more warlike tribes, the gentle people of the shaman Azazruk journey to the Aleutian Islands. As a benevolent shaman who serves his people instead of using them, Azazruk is directly contrasted to Oogruk's power-hungry shaman. With Azazruk, Michener illustrates the influence which a positive spiritual leader can have on his people. In their new home, Azazruk and his people are enchanted by a mother sea otter which, with an almost human face, floats on her back, resting her baby on her stomach. For Azazruk, the sea otter becomes a symbol of peace and maternal love, but for most of his people, hunting the silky-furred otters becomes impossible to resist.

As a part of his effort to expand Russia's sphere of influence, Tsar Peter the Great orders the Dane, Vitus Bering, to explore Alaska. In the chapter "The Explorers," the historical Vitus Bering and his fictional companion, the Cossack Troflin Zhdanko, set out on a true odyssey, one which takes them eight years from St. Petersburg, across eighteenth- century Russia, to Siberia and Alaska. Russian imperialism and Russian explorers have a disastrous effect on Alaskan natives (both human and animal), for most of the Russian explorers lack Zhdanko's moral strength. One of the worst offenders is his stepson, ironically named Innokenti (Innocent), who exploits the Aleuts and their environment. Innokenti, like most of the Russians, feels no more remorse when he kills an Aleut than when he clubs the beautiful sea otter for its pelt; after all, an Aleut is "not human."

One Aleut who survives the extermination of her people is fourteen-year-old Cidaq. To further the decimation of the Aleuts, the Russians strip Cidaq's island of all its male inhabitants. Although there is food in the Arctic waters, Cidaq's people believe that hunting and kayaks are forbidden to women. Cidaq's courage is reinforced by that of her grandmother, Old One, who convinces her not only to touch the forbidden kayaks, but to embark on a whale hunt. Old One's courage and her determination to survive force her to "sell" Cidaq to Rudenko, a Russian criminal. Old One understands that the people of the island are doomed, and even a bad life for Cidaq is better than no life at all.

Two important aspects of civilization are brought to Alaska at almost the same time — the Russian church and the Russian state. Father Vasili Voronov, an idealistic young Russian Orthodox priest, whom Michener based on a historical figure, is sent to Alaska to bring enlightenment to the Aleuts. The title of this section, "The Duel," reflects the battle between Father Vasili and the last Aleut shaman for the minds and the souls of all the Aleuts, and for one Aleut in particular — Cidaq. Raped and tortured by her Russian "rescuer," Cidaq represents all the Aleuts who have been brutalized by Russian exploitation. Although she is Father Vasili's first convert, his rigid Christian philosophy decrees that she must become God's instrument to save Rudenko. Sincere in his good works, Father Vasili sees Aleuts and Creoles (the children of an Aleut and a Russian) as human, yet he renounces his marriage to Cidaq (now christened Sofia), and this "saint" leaves Alaska to become Metropolitan of All the Russians.

Aleksander Baranov, a major historical figure, bears the standard of law and order for Russian merchants when he is sent to Alaska to govern the territory and to insure their profits. Like Father Vasili, Baranov sees Aleuts and Creoles as the future of Russian America. Although Baranov is an able governor in both the Aleutians and in Sitka, he meets with adversities: rebellious Tlingit Indians and arrogant Russian aristocrats, who believe that only the upper class should rule. The Tlingits, who are led by the historical Kot-le-an and the fictional Raven-heart, prove to be worthy opponents as they repeatedly try to recover their stolen land. Honored for his courage and compassion by his enemy Raven-heart, Baranov is defeated by his countrymen. He leaves Sitka in 1819, a prisoner aboard a Russian warship and dies in chains before he reaches Russia.

When Russia sells Alaska to the United States in 1867, Alaska gains a new master, but not a better one. Since no one in Washington knows what legal status to give this new possession, Alaska has no law, Alaskans have no protection, and both become the prey of Captain Emil Schransky and his dark ship Erebus. Looking like a Calvinist image of God the Father, with Nordic white hair and long full beard, Schransky slaughters gravid female seals and rips unborn cubs from their mothers' wombs. Worse is Schransky's exploitation of the Eskimos. Because he illegally sells them rum, entire villages of men, women, and children are wiped out. The Reverend Sheldon Jackson and Captain Michael Healy are an unlikely pair who unite to defeat Schransky. A "born missionary," Jackson hates Catholics, Mormons, Democrats, and alcohol. Healy is the "profane and hard-drinking" son of an Irish-Catholic father. That he is also the child of a black Georgia slave woman makes him a perfect foil for the white-bearded Schransky and his dark ship.

Other Americans who damage Alaska ecologically, politically, and economically include Portland merchant Malcolm Ross, who controls the goods which are shipped to Alaska and the ships which carry the goods; and Tom Venn, Ross's son-in-law, who builds one of the first salmon factories and is largely responsible for endangering the sockeye salmon. Although Ross and Venn convince themselves that their Alaskan "icebox will never have enough people to become a state," they are shrewd enough to hire Marvin Hoxey to prevent national legislation that would give Alaska home rule.

The years between 1897 and 1898 bring hordes of people stampeding through Alaska when an enterprising Portland reporter writes that a "ton of gold" has been discovered in the Klondike in Canada. In "Gold," Michener again focuses on the incredibly complicated and dangerous process of the journey itself by detailing the journeys of two of the major characters in the novel: John Klope and Missy Peckham. Klope, a poverty-stricken farmer from Moose Hide, Idaho, reaches the Klondike in four months. Succeeding only because of his stubbornness and his physical strength, he takes the route of the Yukon River, which freezes before he can reach his goal. In subzero weather, he walks fifty miles to Fort Yukon, then dog sleds the final stage to Dawson City to stake his claim.

Social worker Missy Peckham, her lover Buck Venn, who is on the run from the Chicago police, and his young son Tom take the route through Chilkoot Pass, which separates the American and Canadian borders. Canadian law requires Missy and each member of her party to carry two thousand pounds of supplies (food for the entire year) up the snow-covered Chilkoot so they will be self-sufficient in Canada. During her travels Missy is victimized by Alaska's lack of government. She meets Soapy Smith, who robs and kills gold miners; the Belgian Mare, a madam who imports her girls from Europe; and Will Kirby, a congenial Mountie who becomes her lover after Buck Venn is killed. John Klope finds gold, but it "slowly slips through his fingers"; Missy finds, not gold, but the Irishman, Matt Murphy (his fatal MacKenzie River route across Canada is the section which becomes Journey); and Tom Venn opens a store and becomes one of the wealthiest men in Alaska.

"The Railbelt," which follows the relationships of families already introduced (or their descendants), also adds several new characters. Looking for a place to build Malcolm Ross's salmon cannery, Tom Venn meets two descendants of the Tlingit Raven-heart, Tom Bigears, and Tom's daughter Nancy. Although the Bigears family have owned their land for generations, Ross has no trouble dispossessing them of their rights. After removing thirty-two thousand crates of salmon from the Bigears' river, Ross "graciously" gives Torn Bigears permission to take one or two salmon a year. During the Great Depression, when Minnesota farmers Elmer and Hilda Flatch are given an all-expenses-paid ticket to Alaska by the U.S. government, Missy Peckham, now an outspoken advocate of Alaskan statehood, is on hand to greet the new arrivals. Later, young LeRoy Flatch helps to provide a much-needed means of transportation when he becomes a bush-pilot, while Flossie Flatch, over the objections of her parents, marries Nate Coop, an illiterate half-breed. The three male members of the Flatch family all contribute to the war effort during the 1940s: LeRoy, who joins the Air Corps, flies cargo planes to Moscow across the Arctic Circle; Elmer helps build the first Alaskan highway, the fourteen-thousand-mile Alcan; Nate Coop, who joins the Alaska Scouts, takes part in a bloody defense of the Aleutians when the Japanese invade in 1943.

"The Rim of Fire" is an appropriate title for the last section. Alaska not only rests on an area of geological upheaval, it is in the throes of economic, ecological, and political upheaval. The greatest victims are its native peoples, as Kendra Scott begins to realize when she teaches Eskimo children at Desolation Point. In spite of government legislation to return native land, and in spite of education, the Eskimos of Alaska are an endangered species. Alcoholism and suicide run rampant in their culture. When the Native Claims Settlement Act is passed in 1971, two kinds of lawyers move to Alaska. They are represented by Jed Keeler, pragmatic but honorable, and Poley Markham, whose motto is "No matter what you do, leave a trail of paper proving that you didn't do it." At the end of the novel, Jed Keeler dies, swept out to the ocean with the tsunami, leaving Poley Markham and the Poleys of the world in possession of Alaska.