Along the Pacific coast glaciers, some of them remarkable for their extent and grandeur, fill the principal mountain gorges, and terminate at the sea in magnificent masses of overhanging ice. The fact that these glaciers are gradually decreasing in size from year to year leads to the inference that the rigor of the climate is slowly mitigating. Hot and mineral springs are found near Sitka, on the Aleutian islands and the neighooring coast, and in other parts of the territory. In the Alexander archipelago fossils of the cretaceous period have been found, but the extent of the formation has not been ascertained. Clay slates and conglomerate occur near Sitka. Crystalline white marble of fine quality has been discovered on Lynn channel and in other portions of the archipelago. Thence northward to Mt. St. Elias granite and metamorphic rocks skirt the coast. In the Aleutian islands the tertiary formation is of considerable extent, and contains coal, lignite, and amber. The best deposit of tertiary coal, so far as known, is on Cook's inlet, where it occurs in two parallel layers, with an estimated thickness of from 18 inches to 7 feet.

Gold and silver are found in Alaska in small quantities; and copper is frequently brought to the settlements by Indians dwelling on the Copper river, who sedulously conceal the locality of its origin. Cinnabar and iron have been found in very limited quantities. Of sulphur the volcanic districts of the territory afford an abundant supply. - The fossils found in Alaska show that it was once the home of the elephant, the buffalo, and the horse. Bears are now the largest animals native to the country. Of these, the polar or white bear (ursus maritimus) is met with on the Arctic coast; the black bear (U. Americanus) in the woody districts of the Yukon; and the barren-ground bear (U. Richardsonii) in the far northeast. The grisly bear (U. horribilis) is also occasionally encountered. Of the other non-marine fur-bearing animals the principal are the fox, the beaver, the marten, the otter, the mink, the lynx, and the wolverene. On the coasts are found the fur seal, the main source of revenue in the territory; the sea lion, closely allied to the former; the sea otter, an animal of solitary habits living almost exclusively in the water; and the walrus, from which the natives obtain their ivory and oil.

In the adjacent seas whales are abundant, and cod, herring, and halibut are found in prodigious numbers, at the proper seasons. A small fish called the ulikon, upward of a foot in length and of a silvery hue, is also very abundant along some parts of the coast, and is remarkable as being the fattest of all known fish. The various species of salmon which throng the Alaskan rivers occur in numbers so great as almost to exceed belief. The weak and injured fish which die after spawning time are sometimes thrown up along the river banks by the waves, to the depth of three or four feet. Immense quantities of salmon and other river fish are caught and dried. In summer, Alaska is the nesting place of myriads of migratory birds. Geese and ducks, swans, ospreys, eagles, and gulls arrive about the first of May from southern latitudes, and remain till early autumn, when they leave the country to the ptarmigan, the white hawk, and the arctic owl. The rich berries of the interior afford them excellent food. Here the nests of the canvas-back duck, so long sought for in vain in other regions, were first discovered. Mosquitoes abound during the summer months along the Yukon valley.

Beetles and several varieties of butterfly are known to occur. - The natives of Alaska may properly be classed into two divisions: the Esquimaux and kindred tribes, and the Indians. To the first belong the inhabitants of the Aleutian islands, and the Innuits, who are settled on the islands along the coast from Behring strait to Mt. St. Elias. Their intercourse with the Russians has deprived the Aleuts of all their national characteristics; but they are as yet by no means civilized, though many of them profess the Christianity of the Greek church. Hunting the fur seal and sea otter is their principal occupation. Of the Indians, the Co-Yukon is the largest tribe on the Yukon river. They dwell during the winter in underground huts, and are greatly feared by the surrounding natives of other tribes, on account of their fiercer nature and superior prowess. - The fisheries and the fur trade are the leading industries of the territory. In 1870 the product of the fishery, in salted codfish alone, was 10,612,000 lbs. The taking of fur seals, which is for the most part restricted to the Pribyloff islands, is now regulated by act of congress, the privilege being under rental to a corporation at $55,000 per annum.

The yield has been much diminished by the unwise and indiscriminate slaughter permitted in past years, but under the present regulations a steady production of 100,000 skins per annum can probably be secured. In 1869, 85,901 seals were taken on St. George's and St. Paul's. The average annual yield of the sea-otter skins is 1,300, and they are worth $100 each. In 1867-'8 furs to the amount of $100,000 were produced by the Yukon district, and the average product is not less than $75,000 worth per annum. The total annual yield of furs from the rest of the continental portion of Alaska does not exceed $10,000 in value. There is a small trade in ice with California, and timber is exported in limited quantities. A large proportion of the whale oil and bone taken by the Behring sea whaling fleets is derived from Alaskan waters. - Russia acquired her American possessions by virtue of the right of discovery. On July 18, 1741, Vitus Behring, the celebrated Russian explorer, discovered the rocky range of mountains, the crowning peak of which is Mt. St. Elias. Subsequently, and during the same voyage, he visited many of the Aleutian islands, until finally he was overtaken by death at that which bears his name.

In 1778 Captain Cook, the English navigator, explored the Alaskan coast, and sailed far up into the bay now known as Cook's inlet, in hopes that it would prove the northern passage homeward to Great Britain. Numerous Russian commercial expeditions visited the new region, and in 1783 a trading establishment was opened on the island of Kadiak. Similar enterprises followed in other localities; and in 1799 the Russian-American fur company was organized under sanction of the emperor Paul, by a consolidation of all the companies then existing in the territory. This corporation was granted the exclusive right of hunting and fishing in the American dominion of the czar. It established a line of forts and trading posts along the coast from Norton sound southward, with occasional stations further inland, and after Sitka was founded the headquarters were removed from Kadiak to that place. The country was ruled by the company, the chief director of which exercised absolute sway throughout the colony till 1862, when, the charter having expired, the government declined to renew it, in consequence of the abuses which had grown up. The company, however, continued in control by permission of the home authorities.

In 1865-7 the territory was explored by a scientific corps sent out from the United States to select a route for the Russo-American telegraph line, a project which was abandoned in consequence of the successful laying of the Atlantic cables. Negotiations were begun in 1867 for the purchase of the country by the United States; $7,200,000 was the price agreed to be paid, and the treaty was ratified by the senate on May 20 of the same year. On Oct. 18 Brig. Gen. Lovell H. Rousseau of the United States army, having been appointed commissioner for that purpose, formally took possession of the territory in the name of the United States. Alaska constitutes a military and collection district, with headquarters at Sitka. - See "Travels and Adventures in Alaska," by Frederick Whymper (London, 1869), and "Alaska and its Resources," by W. H. Dall (Boston, 1870).