Union Pass is a strategically located passageway through the mountains of northwestern Wyoming. The pass location, at an elevation of 9,210 feet, is in a hub or core area from which three great Wyoming mountain ranges rise in gradually ascending elevations to heights of 13,000 feet or more as they radiate in three separate directions--the Wind River Range to the southeast, the Gros Ventre Range to the west and the Absaroka Range to the north. The Union Pass area, some 4,000 feet lower than mountains surrounding it on all sides, offers an easy common passageway among the headwaters of three great river systems, the Colorado, the Columbia and the Missouri. It was an important mountain crossing, north and south as well as east and west in both historic and prehistoric times.