THE NORTHLANDS

T he United States is in many ways a creation of a frontier experience. The push westward remains part of recent American history, and many still live who remember the days of early settlement, of the often heroic struggle with the land.

The American frontier is largely gone today. Although humans presumably have the technology to live anywhere on the earth's surface, those areas of the United States that can be occupied with moderate physical and economic effort are already staked out.

Extending as far south as the northern Great Lakes states and including the interior to the Canadian border, as well as parts of Alaska, the Northlands (Map 15: 19K) remains sparsely settled. The inhospitable nature of the physical environment plus the consequent thinness of settlement give the Northlands its special character.

A HARSH ENVIRONMENT

If Americans were asked to describe the Northlands, "cold" would probably be the most commonly used adjective. Average January temperatures range from a high of about -7°C along its southern Great Lakes margin to a full -40°C in parts of Alaska. Temperatures can reach -60°C.

Not only are winter temperatures low across most of the region, but winters are long. The average time between the last frost in the spring and the first in the fall is roughly 135 days at the southern margins of the area but little more than 14 days along parts of the Arctic Ocean. Because virtually all major food crops need a growing season of longer than 90 days, they can be grown in only a few small areas along the southern margins.

Summers, generally short and cool, can have surprisingly warm days. Maritime moderation is significant only along the peripheries, mainly in the east and west.

This dramatic seasonal variation in temperature results from the great shifts in length of day and the angle of incidence of the sun's rays. As the Earth follows its annual path around the sun, the North Pole is tilted toward the sun during what is summer in America and away from it in winter. Thus, everywhere north of the Arctic Circle is in darkness for at least one day at midwinter and experiences at least a 24-hour period without the sun setting at midsummer. Moreover, during the winter, the sun, when it rises, remains low on the horizon. Even southern sections of the region receive only six or seven daylight hours during the winter.

Precipitation amounts vary widely across the Northlands. Highest levels are found in the far southeast, where both winter and summer storm systems dump more than 100 centimeters of annual precipitation along the southern shore of Labrador. Precipitation levels drop markedly toward the interior and north.

Despite the paucity of precipitation, little of the Northlands provides the appearance of a dry environment. In the summer, in fact, much of the region is covered with standing water. This is due, in part, to the low levels of evaporation and evapotranspiration found in this cold climate. In the northern portions of the region, standing water is also supported by the widespread existence of permafrost--a subsurface layer of permanently frozen ground that is commonly about 100 meters thick and sometimes extends downward for more than 300 meters. In warmer areas, the permafrost is discontinuous, with areas of frozen ground interspersed with unfrozen soil. As the surface layer thaws during the short summer to a depth of perhaps 1 meter, water is held on the surface by the frozen layer underneath, creating a boggy, shifting surface.

Construction in permafrost is difficult. Buildings must be placed on piles sunk deeply into the permafrost for stability, and roads must be repaired extensively each year to maintain any resemblance of an even roadbed. Most of Alaska is underlain by continuous or discontinuous permafrost.

Although considerable local terrain variation is found, much of the Northlands topography is either flat or gently rolling. The north slope of Alaska, for example, is a broad, flat coastal plain.

Northlands soils are varied but are generally acidic, poorly drained, and of low agricultural quality. Soils in the southern portion of the region are mostly boralfs or spodosols soils of a cool needleleaf forest environment. To the north, tundra soils, often water saturated and frozen, dominate. Fertile soil is confined to some of the old river valleys and to those lakes that have been filled by sedimentation and decayed vegetation.

Most of the Northlands can be placed in two distinct vegetation areas. Stretching across the southern arc of the region is a coniferous forest called the boreal forest, or taiga. Covering hundreds of thousands of square kilometers, these closely ranked spruces, firs, pines, and tamaracks appear to blanket the landscape in a dark, almost black mass when seen from the air. Slow growing and never really tall, these trees decrease in number and height from south to north across the taiga. Around the Great Lakes, a mixture of pines and hardwoods predominate.

Passing just south of Hudson Bay, then angling northwest to the mouth of the Mackenzie River and across the northern edge of Alaska, is the tree line, which identifies the transitional zone between the taiga and tundra in the Northlands. North of it, climatic conditions are too harsh for tree-like vegetation. Beyond lies the tundra, a region of lichens, grasses, mosses, and shrubs.

The great Arctic ice pack, covering some 4.8 million square kilometers, is a thin (usually 3 to 6 meters thick), rugged sheet of nearly salt-free ice floating on the Arctic Ocean. It holds as much water as all the freshwater lakes in the world. In winter it extends southward to enshroud northern Alaska. Summer melt briefly frees the area.

The ice limits ocean transport in the Arctic to a brief, often hectic period each summer. An early return of the ice can sometimes block ships (and whales that migrate into the Arctic Ocean during the summer) from escaping to open water to the south. The ice also minimizes any moderating impact by the Arctic Ocean on the Northlands' climate.

HUMAN OCCUPATION

Nearly all parts of the Northlands are sparsely populated, with highest densities found along the southern margins. American Indians, Metis, and Inuit (Eskimos) are numerically dominant over much of the region north of the United States. Inuit are the predominant population in most of the Arctic. American Indians are found mainly in the boreal forest area. The Metis are the result of intermarriage between American Indian women and whites during the early fur trading period of European settlement in the taiga.

The arrival of Europeans in the Northlands brought an end to much of the American Indian and Inuit traditional culture. Fur traders early acquired many of their pelts from the Indians of the taiga, and European goods entered the Indian economy as a result. Where hunting and fishing continue, the motorboat, rifle, and snowmobile have usually replaced the kayak, bow, and dogsled. But most Northlands Indians and Inuit no longer exist by hunting and fishing. They have moved in substantial numbers into towns, and many urban places of the Northlands today have large native populations.

The Northlands offered little of interest to most Europeans who came to America. Where Northlands settlement did occur, its focus was usually either extractive or military. French voyageurs, fur trappers, and traders pushed their canoes far beyond the agricultural settlements along the lower St. Lawrence River as early as the middle of the 17th century, extending French political control across the Great Lakes. The Hudson's Bay Company, an early British fur trading company, established itself on the margins of Hudson Bay in Canada and then pushed south and west, thus blocking further French expansion westward. By the mid-18th century, the Hudson's Bay Company, which had been granted a trade monopoly to the area by the British government, was in control of the entire boreal forest reaching from Hudson Bay westward to the Rocky Mountains, with further extension of influence into the Arctic. This vast extractive empire brought with it only a minimal number of small and widely scattered settlements.

The voyageurs and Hudson's Bay Company relied on the numerous lakes and streams of their area for transportation, and they located small forts at control points along the water routeways. At places where important streams met lakes, where streams ended and an overland portage began, or where rapids or falls were encountered, vessels had to be unloaded and their goods moved and reloaded onto other boats; these points provided effective control of the entire water system. The sites of many early French forts are occupied today by important urban centers, including Chicago, Detroit, and Pittsburgh.

The boreal forest of the southern half of the Northlands contains the largest area of uncut forest remaining in North America. Until recently, the lumbering and the pulp and paper industries only nibbled at the edges of this vast forest. The area of the upper Great Lakes was logged on a massive scale during the late 1800s and the early 20th century. Because little reforestation was practiced at that time and because the cold climate of the boreal forest slows regrowth, much of this area is only now recovering its previous appearance.

The portion of the Northlands in the upper Great Lakes area is America's leading source of iron ore plus a substantial contributor of copper. Alaskan North Slope petroleum has recently provided a large addition to the American energy supply, presently pumping about 25 percent of the country's total production.

As with logging, the accessible peripheries of the Northlands became the region's first important mining districts. The Mesabi Range in northern Minnesota, an area of gently rolling elongated hills, along with neighboring areas in Minnesota, Wisconsin, and Michigan, developed into America's chief source of iron ore late in the 19th century. Billions of tons of high-grade ore were moved by rail to Lake Superior ports and loaded there onto large specialized lake ships that carried the ore to ports in northeastern Ohio, where it was transferred to railroads for the trip to iron- and steel-processing plants in the Pittsburgh-Youngstown area. Today, most ore goes to the newer, integrated iron and steel facilities at the southern end of Lake Michigan. L