Union Pass is a high mountain pass

Mountain pass

A mountain pass is a route through a mountain range or over a ridge. If following the lowest possible route, a pass is locally the highest point on that route...

 in the Wind River Range

Wind River Range

The Wind River Range , is a mountain range of the Rocky Mountains in western Wyoming in the United States. The range runs roughly NW-SE for approximately 100 miles . The Continental Divide follows the crest of the range and includes Gannett Peak, which at 13,804 feet , is the highest peak...

 of western Wyoming

Wyoming

Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. The pass is located on the Continental Divide

Continental Divide

The Continental Divide of the Americas, or merely the Continental Gulf of Division or Great Divide, is the name given to the principal, and largely mountainous, hydrological divide of the Americas that separates the watersheds that drain into the Pacific Ocean from those river systems that drain...

 between the Gros Ventre mountains on the west and the Wind River Range on the east. The pass was historically used by Native Americans

Native Americans in the United States

Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

 and early mountain men including the Astor Expedition

Astor Expedition

The Astor Expedition of 1810-1812 was the next overland expedition from St. Louis, Missouri to the mouth of the Columbia River after the Corps of Discovery, led by Lewis and Clark.-History:...

 in 1811 on its way west. On the return trip, fearing hostile Indian activity near Union Pass, the Astorians chose a southern route and discovered South Pass

South Pass

South Pass is two mountain passes on the Continental Divide in the Rocky Mountains in southwestern Wyoming. The passes are located in a broad low region, 35 miles broad, between the Wind River Range to the north and the Oregon Buttes and Great Divide Basin to the south, in southwestern Fremont...

.

The pass was named by U.S. Army Captain William F. Raynolds

William F. Raynolds

William Franklin Raynolds was a U.S. Army Colonel, explorer, engineer, Mexican War and Civil War officer who is best known for leading the 1859-1860 Raynolds Expedition while serving as a member of the U.S. Army Corps of Topographical Engineers...

 in 1860. Raynolds was in charge of the Raynolds Expedition

Raynolds Expedition

The Raynolds Expedition was an United States Army exploring and mapping party which left St. Louis, Missouri May 29, 1859 and was intended to map the unexplored territory between Fort Pierre, Dakota Territory and headwaters of the Yellowstone River. Led by experienced explorer and topographical...

 which was exploring the Yellowstone

Yellowstone National Park

Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...

 region immediately prior to the Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

. After mountain man and guide Jim Bridger

Jim Bridger

James Felix "Jim" Bridger was among the foremost mountain men, trappers, scouts and guides who explored and trapped the Western United States during the decades of 1820-1850, as well as mediating between native tribes and encroaching whites...

 led the expedition over the pass, Raynolds gave the pass its current name.

An unimproved dirt road crosses the pass, connecting U.S. Route 287

U.S. Route 287

U.S. Route 287 is a north–south United States highway. It is long. It serves as the major truck route between the Texas cities of Fort Worth and Amarillo...

 near Dubois

Dubois, Wyoming

Dubois is a town in Fremont County, Wyoming. The population was 962 at the 2000 census, although it nearly doubles in the summer with many part-time residents.-Geography:...

 to U.S. Route 189

U.S. Route 189

U.S. Route 189 is a spur of U.S. Route 89. It currently runs for 322 miles from Provo, Utah at Interstate 15 to Jackson, Wyoming. The highway was not part of the original 1926 U.S. Highway system. The highway was created in the 1930s, absorbing former U.S. Route 530 and a portion of U.S. Route 30S...

 in Pinedale

Pinedale, Wyoming

Pinedale is a town in and the county seat of Sublette County, Wyoming, United States. The population was 1,412 at the 2000 census. Pinedale is an important hunting outfitting town and a gateway to the Wind River Mountains. It is also a major gateway to the Jackson Hole area in Wyoming. Pinedale is...

.

External links

• Union Pass at the Wyoming State Historic Preservation Office