Arctic coast, have ascertained that these mountains preserve a strongly defined outline entirely to the sea, and hang in towering cliffs over it, {221} and by other surveys have discovered that they gradually increase in height from the sea southward.
The section to which the term Rocky Mountains has been applied, extends from latitude 58° to the Great Gap, or southern pass, in latitude 42° north. Their altitude is greater than that of any other range on the northern part of the continent. Mr. Thompson, the astronomer of the Hudson Bay Company, reports that he found peaks between latitudes 53 and 56 north, more than twenty-six thousand feet above the level of the sea.[21] That portion lying east of Oregon, and dividing it from the Great Prairie Wilderness, will be particularly noticed. Its southern point is in the Wind River cluster, latitude 42° north, and about seven hundred miles from the Pacific Ocean. Its northern point is in latitude 54° 40['], about seventy miles north of Mount Browne,[22] and about four hundred miles from the same sea. Its general direction between these points is from N. N. W. to S. S. E.
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 furnorth, not far from Athabasca Pass. It was formerly thought to be above 15,000 feet in height, but recent measurements have reduced it to less than 10,000.—Ed.]
