Passing to the east side, we find the plateau country at its north corner extending to the Idaho line where the foot-hills of the Rocky Mountains begin, and soon rise into the Cœur d'Alene Mountains.Cœur d'Alene Mountains, which—being the local name for part of the Bitter Root Range—is a part of the western branch of the Rocky Mountains. The Cœur d'Alene River and Lake belong to the Columbia River basin, and are so naturally connected in mining and trading interests with Washington Territory, that in another connection I shall have much to say of the Cœur d'Alene country, as also of the Colville country, and other parts of the mountain rim. South of the Cœur d'Alene Lake the plateau country extends far into Idaho, and gives to that State its best farming lands.
The Blue Mountains which mark the southern limit of the plateau in Washington Territory do not extend more than half-way across the plain, leaving a long projection of the plateau to extend southward into Oregon.
The Great Plateau.The shape of the plateau in Washington Territory is an irregular square with a diameter each way of about 150 miles. Followed into Idaho and Oregon, the diameters would reach 200 miles. Its surface is generally smooth, but there are frequent patches of rock, and sometimes large areas are roughened by rocky outcrops. The plateau is elevated and rolling, rising from 1,000 to 3,000 feet above the surface of Columbia River. Its elevations usually are mere swells, except along the precipitous edges of coulées. I know of only one mountain upon it, and that is quite a small one; but it served as a refuge for Lieutenant Steptoe and his handful of soldiers when attacked by the Indians; and hence is called Steptoe Butte. The surface of the plain is scarred in a number of places with couléesCoulées., or dry river-beds, which are cut down twenty to one hundred feet, and sometimes more, and their sides are usually marked by bluffs, often of rock. These coulées are an advantage, or a disadvantage, in road-making, according to whether the road goes with, or across, the coulée. The Northern Pacific Railroad found it convenient to use one of them for a long distance. The deepest cuts in the plateau are made by its rivers. Of these the Columbia is chief. This river, as already intimated, has cut a channel for itself along the north and west edge of the plain from 1,000 to 2,000 feet below the general level. The Snake River, which is the largest affluent of the Columbia, has numerous branches, all cut deep into the basalt which underlies the plain.
Columbia and Snake Rivers.The Columbia and Snake are both steamboat rivers, but navigation is interrupted by rocky rapids, which prevent through lines of steamers. The Columbia is one of the largest rivers in the world, and has abundant water for steamboats from its mouth to a point in Canada, north of Farwell, where it is crossed by the Canadian Pacific Railway, and steamboats run at intervals to the most northerly point; and there are navigable stretches not yet used for boats which will have steamers in connection with future railroads. The steamers on Snake River are very useful, and run to Lewiston, in Idaho, and perhaps further.
This plateau, or Great Plain of the Columbia, as it is called sometimes, is a most interesting and important region, concerning which I shall have much to say under subsequent heads.
ALTITUDES IN WASHINGTON TERRITORY.
| FEET. | ||
| Mount Ranier (Tacoma) | 14,444 | |
| Mount Baker | 10,827 | |
| Mount Adams | 9,570 | |
| Mount St. Helens | 9,750 | |
| Natchess Pass | 4,900 | |
| Stampede Pass, Summit | 3,980 | |
| Tunnel, Stampede Pass | 2,885 | |
| Snoqualmie Pass | 3,110 | |
| Kechelus Lake | 2,388 | |
| Kachess Lake | 2,158 | |
| Ellensburg | 1,518 | |
| Yakima City | 990 | |
| Ainsworth | 351 | |
| Palouse Junction | 858 | |
| Sprague | 1,200 | |
| Spokane Falls | 1,910 | |
| Colville | 1,917 | |
| Fort Spokane | 1,300 | |
| Okinagane Lake | 1,163 | |
| Great Plain of Columbia River | 1,000 to 3,000 | |
| Snake River, N. P. R. R. | 358 | |
| Colfax | 1,941 | |
| Dayton | 1,360 | |
| Walla Walla | 1,000 | |
| Wallula Junction | 326 |
CLIMATE.
The Climate of Washington Territory.Climate is a matter of temperature, moisture and atmospheric dynamics. The general law of temperature is that the farther north the colder the weather; and yet currents of water and prevailing winds may give to the country a climate geographically belonging to quite a different latitude. We know how this is with England, which, judged by latitude, ought to be colder than Maine, but which, in fact, has one of the mildest and most equable climates in the world. England is farther north than Washington Territory, which latter is in the latitude of France; but it is also in the latitude of Montana, Dakota and Maine, States remarkable for sudden changes and for terrible cold. But it is well known that our Pacific States, at least on their western borders, have a temperature free from extremes in both summer and winter. Taking July and January as the hottest and coldest months, it will be found that the average temperature at San Francisco and Puget Sound is from 7° to 14° cooler than it is in the Rocky Mountains and in New England during the same months. And on the other hand, taking January as the coldest month, we find that Bismarck, Denver, New England, etc., are 30° to 40° colder than the points on the Pacific. In other words, that the range of the thermometer between extremes averages near 50° more in the East than it does in the West in the localities named; a very great difference when we consider comfort, health, cost of living, and opportunity to labor in the open air.
Mild and equable.This greater mildness and equability of temperature on the Pacific Coast is to be ascribed to the winds and currents of the great ocean. During the summer the winds come from the northwest, and during the winter from the southwest and south. Much influence in tempering the cold of winter is ascribed also to the Japan Current, mentioned under a former head. It does for the Pacific Coast what the Gulf Stream does for England.