Hagerman Pass, elevation 11939 ft (3,639 m), 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...

 that crosses the continental divide

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 connected to the open sea...

 in the Rocky Mountains

Rocky Mountains

The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

 of central Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 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 was named for James J. Hagerman, builder of the Colorado Midland Railroad. The Colorado Midland railroad crossed the continental divide through one of two tunnels (initially the Hagerman Tunnel, later the Busk-Ivanhoe Tunnel at lower altitude) near the top of Hagerman pass. It traverses the Sawatch Range

Sawatch Range

The Sawatch Range is a mountain range in central Colorado which includes eight of the twenty highest peaks in the Rocky Mountains, including Mount Elbert, at elevation, the highest peak in the Rockies....

 west of Leadville

Leadville, Colorado

Leadville is a Statutory City that is the county seat of, and the only municipality in, Lake County, Colorado, United States. Situated at an elevation of , Leadville is the highest incorporated city and the second highest incorporated municipality in the United States...

, connecting the headwaters of the Arkansas River

Arkansas River

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

 on the east with the upper valley of the Fryingpan River

Fryingpan River

The Fryingpan River is a tributary of the Roaring Fork River, approximately long, in west central Colorado in the United States.It rises in northeastern Pitkin County, in the White River National Forest in the Sawatch Mountains along the western side of the continental divide. It flows westward...

 above Basalt

Basalt, Colorado

Basalt is a Statutory Town in Eagle and Pitkin counties in the U.S. state of Colorado. The population was 2,681 at the 2000 census.-Geography:...

, in the basin of the Colorado River.

The pass is traversed by an unimproved road that is passable only with four-wheel drive

Four-wheel drive

Four-wheel drive, 4WD, or 4×4 is a four-wheeled vehicle with a drivetrain that allows all four wheels to receive torque from the engine simultaneously...

vehicles and on foot. Two-wheel drive vehicles will find it difficult due to some stream crossings and rocky sections. It is open from approximately late May through the arrival of the first heavy snow in mid or late autumn. The road has occasionally been blocked by fallen trees.