Before entering into a minute discussion of the timber resources and the lumber history of Canada, it is well to review briefly the North American continent in its relation to tree distribution, especially with reference to the United States and Canada, which countries are one in their forest characteristics. While there is one prominent tree species which is almost wholly confined to Canada, and a few others whose native habitat is largely within its area, and while about half of the tree species of the continent, belonging to the southern United States, do not appear north of the international boundary, that arbitrary line of demarcation between the two countries cuts across the mountains, the treeless plains, the forested areas and the lines of tree growth; so that in a discussion of tree distribution the two countries should be treated as one, the differences being determined by soil and climatic conditions which have no relation to political divisions.

It should be noted first that the Atlantic Coast, including its islands, is practically all timbered from the Strait of Belle Isle, or certainly from the northern boundary of the main body of Newfoundland, to the Strait of Florida. The treeline follows the Gulf Coast from near the southern point of Florida to about west of Galveston, Texas, so that the Gulf and Atlantic coasts of the United States, with small exceptions, are timbered.

As the northern arm of Newfoundland is practically barren, so is the Labrador Coast. Starting from the Strait of Belle Isle, the northern forest limit runs a little inland from the coast, following the boundary between Labrador and Ungava to Ungava Bay; thence bending westerly and southerly it strikes Hudson Bay at about 57 degrees north latitude. The northern limit on the western side of Hudson Bay begins farther north, at about Fort Churchill, and follows an approximately straight line northwestward, passing north of Great Slave Lake, to the mouth of the Mackenzie River, north of the Arctic Circle; thence it turns to the southwest through Alaska, striking the coast again in the southwestern part of that American territory.

The Pacific Coast of North America has characteristics quite different from those of the Atlantic Coast, owing to the mountain uplift which closely follows the coast. Instead of a solid and wide body of timber, as is the condition on the Atlantic Coast, there are smaller areas heavily timbered, intersected and separated by mountain areas which are nearly or quite treeless. The presence of the "mountains further results in a semiarid condition farther inland. Practically all the way from Cook Inlet, in Alaska, to the Bay of San Francisco, the coast has a continuous fringe of heavy forest growth, widening out as local topography will permit into the great forests which are found in British Columbia, Washington and Oregon.

The western mountain and plateau country of the continent is more or less timbered throughout, barren plains being crossed or bounded by forested mountain slopes, or the barren mountains of the North being penetrated by tree-lined valleys. This condition obtains, with variations due principally to latitude, all the way from the Alaskan peninsula to the Gulf of Tehuantepec.

Between the widespread and comparatively solid and uniform forests of the East and the broken and varied forests of the West lies the great, almost treeless, interior plain of the continent. The boundaries of this treeless plain may be thus roughly outlined: Starting from Galveston, Texas, the line runs in an approximately northern direction through the eastern part of Texas and the western part of Indian Territory. Thence it turns eastward, crossing the southeastern corner of Kansas, thence across Missouri, thence bending into Illinois and reaching just beyond the Indiana line. Thence in a curve it turns to the north and northwest, striking the Mississippi River in northern Illinois, leaving it in southern Minnesota, and passes north between Red Lake and the Red River of the North. Crossing the international boundary in a northerly direction, it sweeps around Winnipeg to the northwest and strikes about the northwestern corner of Manitoba. Thence northwesterly and westerly it crosses Saskatchewan and northern Alberta, and then, turning again to the southwest and south, follows the line of the Rocky Mountains back along the western border of Alberta, across Montana, Wyoming, Colorado and New Mexico, to and across the Mexican border. West of the latter part of this line is the broken mountain flora previously described.

Within this great interior plain are trees, but few forests, so that in a general way the line described surrounds the great agricultural and grazing section of the continent, the rich agricultural regions east of the prairies having been won from the forest through more than a century of settlement and development.