Note 40 — OREGON EXPEDITION
Reading edition
This is South Pass, so named in contradistinction to the northern passes undertaken by Lewis and Clark. It is not known by whom this mountain passage was discovered, but probably by some of Ashley's parties in 1823. The ascent is so gradual that, although 7,500 feet above sea-level, its elevation is not perceived, and in 1843 Frémont could with difficulty tell just where he crossed the highest point of the divide.—Ed.