The mountain ranges run, for the most part, in parallel lines with the coast, and, rising in many places above the snow line (here found to be 6,500 feet), would naturally produce a difference of temperature between them, and also affect their productions.
Our surveys and explorations were confined, for the most part, to the two first, claiming more interest from being less known, and more in accordance with my instructions.
Mountains.—The Cascade range, or that nearest the coast, runs from the southern boundary, on a parallel with the sea coast, the whole length of the territory, north and south, rising, in many places, in high peaks, from twelve to fourteen thousand feet above the level of the sea, in regular cones. Their {278} distance from the coast line is from one hundred to a hundred and fifty miles, and they almost interrupt the communication between the sections, except where the two great rivers, the Columbia and Frazer’s, force a passage through them.
There are a few mountain passes, but they are difficult, and only to be attempted late in the spring and summer.
A small range (the Claset) lies to the northward of the Columbia, between the coast and the waters of Puget’s Sound, and along the strait of Juan de Fuca. This has several high peaks, which rise above the snow line, but, from their proximity to the sea, they are not at all times covered.[89]
Their general direction is north and south, but there are many spurs or offsets that cause this portion to be very rugged.
The Blue mountains are irregular in their course, and occasionally interrupted, but generally tend from north by east to north-east, and from south to south-west.
In some parts they may be traced as spurs or offsets of the Rocky Mountains. Near the southern boundary they unite with the Klamet range, which runs east and west from the rocky mountains.[90]
{279} The Rocky Mountains are too well known to need description. The different passes will, however, claim attention hereafter. North of 48° the ranges are nearly parallel and have the rivers flowing between them.