This range is generally covered with perpetual snows; and for this and other causes is generally impassable for man or beast. There are, however, several gaps through {222} which the Indians and others cross to the Great Prairie Wilderness. The northernmost is between the peaks Browne and Hooker. This is used by the fur traders in their journeys from the Columbia to Canada.[23] Another lies between the head waters of the Flathead and the Marias rivers. Another runs from Lewis and Clarke’s river to the southern head waters of the Missouri. Another lies up Henry’s fork for the Saptin, in a northeasterly course to the Big-horn branch of the Yellowstone. And still another, and most important of all, is situated between Wind river cluster and Long’s mountains.[24] There are several spurs or lateral branches protruding from the main chain, which are worthy of notice. The northernmost of these parts off north of Fraser’s river, and embraces the sources of that stream. It is a broad collection of heights, thinly covered with pines. Some of the tops are covered with snow nine months of the year. A spur from these passes far down between Fraser’s and Columbia rivers. This is a line of rather low elevations, thickly clothed with pines, cedar, &c. The highest portions of them lie near the Columbia. Another spur {223} puts out on the south of Mount Hooker, and lies in the bend of the Columbia, above the two lakes. These are lofty and bare of vegetation. Another lies between the Flatbow and Flathead rivers; another between the Flathead and Spokan rivers; another between the Kooskooskie and Wapicakoos rivers.[25] These spurs, which lie between the head waters of the Columbia and the last mentioned river have usually been considered in connexion with a range running off S. W. from the lower part of the Saptin, and called the Blue Mountains. But there are two sufficient reasons why this is an error. The first is, that these spurs are separate and distinct from each other, and are all manifestly merely spurs of the Rocky Mountains, and closely connected with them. And the second is, that no one of them is united in any one point with the Blue Mountains. They cannot therefore be considered a part of the Blue Mountain chain, and should not be known by the same name. The mountains which lie between the Wapicakoos river and the upper waters of the Saptin, will be described by saying that they are a vast cluster of dark naked heights, descending from the average elevation of fifteen thousand feet—the altitude of the {224} great western ridge—to about eight thousand feet—the elevation of the eastern wall of the valley of the Saptin. The only qualifying fact that should be attached to this description is, that there are a few small hollows among these mountains, called “holes;” which in general appearance resemble Brown’s hole, mentioned in a previous chapter; but unlike the latter, they are too cold to allow of cultivation.