Fremont Pass is a

mountain pass A mountain pass is a navigable route through a mountain range or over a ridge. Since mountain ranges can present formidable barriers to travel, passes have played a key role in trade, war, and both Human migration, human and animal migration t ...

in central

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

, in the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

of the

western United States The Western United States (also called the American West, the Western States, the Far West, the Western territories, and the West) is List of regions of the United States, census regions United States Census Bureau. As American settlement i ...

. It forms the

continental divide A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not ...

on the border between Lake County and Summit County. The pass is named for

John C. Frémont Major general (United States), Major-General John Charles Frémont (January 21, 1813July 13, 1890) was a United States Army officer, explorer, and politician. He was a United States senator from California and was the first History of the Repub ...

, an explorer of the

American West The Western United States (also called the American West, the Western States, the Far West, the Western territories, and the West) is census regions United States Census Bureau As American settlement in the U.S. expanded westward, the mea ...

who discovered the pass while traversing present-day Colorado during the 1840s. The pass provides a route between the upper valley of the Blue River, a tributary of the

Colorado River The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...

, with the headwaters of the

Arkansas River The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in Colorado, specifically ...

to the south. The pass summit is the site of

Climax Mine The Climax mine, located in Climax, Colorado, United States, is a major molybdenum mine in Lake and Summit counties, Colorado. The operations encompass approximately 14,350 acres, consisting primarily of patented mining claims and other fee la ...

, a

molybdenum Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals hav ...

mine. The pass is traversed by State Highway 91. Despite being one of the highest mountain passes in the state, the only steep part is the switchback on the final ascent toward the Climax mine on the south side. The rest of the pass is gentle.

Climate

Railway

The Denver, South Park and Pacific Railroad built a

narrow gauge A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge (distance between the rails) narrower than . Most narrow-gauge railways are between and . Since narrow-gauge railways are usually built with Minimum railw ...

railway over Fremont Pass in 1884. It was sold in foreclosure proceedings to the Denver, Leadville & Gunnison Railroad in 1889 and became later part of the

Colorado and Southern Railway The Colorado and Southern Railway was an American Railroad classes#Class I, Class I railroad in the western United States that operated independently from 1898 to 1908, then as part of the Chicago, Burlington and Quincy Railroad until it was ...

. Operating ended in 1937. The line south of

Climax Climax may refer to: Language arts * Climax (narrative), the point of highest tension in a narrative work * Climax (rhetoric), a figure of speech that lists items in order of importance Biology * Climax community, a biological community th ...

is retained, converted to in 1943 and now operated by

Leadville, Colorado and Southern Railroad The Leadville Railroad is a tourist railroad based in Leadville, Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. I ...

. A second narrow gauge railway line was built by

Denver and Rio Grande Railroad The Denver and Rio Grande Western Railroad , often shortened to ''Rio Grande'', D&RG or D&RGW, formerly the Denver & Rio Grande Railroad, was an American Class I railroad company. The railroad started as a narrow-gauge line running south fro ...

in 1881. Passenger service ceased in late 1909 and the last sporadic freight service in November 1910. The line was abandoned on 1 December 1923.

Electrical Power

In 1909, the Shoshone Transmission Line was built to connect a generating station near

Glenwood Springs Glenwood Springs is a home rule municipality and the county seat of Garfield County, Colorado, United States. According to the 2020 United States census, the city has a population of 9,963. It is located at the confluence of the Roaring Fork ...

with

Leadville Leadville ( ) is a List of municipalities in Colorado#Statutory city, statutory city that is the county seat, the most populous community, and the only List of municipalities in Colorado, incorporated municipality in Lake County, Colorado, Lak ...

and

Denver Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...

. This historic electric transmission line has been modernized several times and is still in use, although the development of the

Climax mine The Climax mine, located in Climax, Colorado, United States, is a major molybdenum mine in Lake and Summit counties, Colorado. The operations encompass approximately 14,350 acres, consisting primarily of patented mining claims and other fee la ...

has caused major changes to the line in the vicinity of the pass.

References

External links

USGS TopoZone listing
Rail mountain passes of the United States Mountain passes of Colorado Landforms of Lake County, Colorado Denver and Rio Grande Western Railroad Transportation in Lake County, Colorado {{Colorado-geo-stub