Alpine Tunnel facts for kids

The Alpine Tunnel is a 1,772 ft (540 m) long narrow gauge railroad tunnel in Colorado, USA. It is located east of Pitkin, Colorado. This tunnel was part of the old Denver, South Park and Pacific Railroad route. This route connected Denver to Gunnison.

At an elevation of 11,523 feet (3,512 m), it was the first tunnel built through the Continental Divide in Colorado. The Continental Divide is like a giant mountain ridge. It separates rivers that flow to the Atlantic Ocean from those that flow to the Pacific Ocean. The U.S. Forest Service says it is still the highest railroad tunnel. It is also the longest narrow gauge tunnel in North America.

Building the tunnel started in January 1880. It was supposed to take only six months. But it took much longer, finally finishing in July 1882. The train line was closed in 1910. This was because of some small damage inside the tunnel. Today, the tunnel is sealed shut. The old train tracks are now a trail for hikers and bicyclists.

A Look Back: Building the Alpine Tunnel

Planning and Construction Challenges

Engineers started planning the tunnel in December 1879. They figured out where the tunnel would begin and end. Construction began in 1880 and finished in 1881. The tunnel was "holed through" (meaning the two sides met in the middle) on July 26, 1881.

This was the highest and most expensive tunnel built at that time. Its highest point is 11,523.7 feet (3,512.4 m) above sea level. It is about 500 feet (150 m) under Altman Pass. This pass was later renamed Alpine Pass. The tunnel itself is 1,825 feet (556 m) long. It took 18 months to complete. Most of the work happened during the cold winter months.

The railroad company, DSP & P, thought the tunnel would go through solid rock. They expected it to be done in about six months. However, the tunnel mostly went through loose rock and clay. This ground was very unstable. It needed a lot of timber supports to keep it from collapsing. This extra work caused the construction to take much longer than planned.

Why the Tunnel Closed

The tunnel was closed in 1910 by the Colorado & Southern railroad company. There was only minor damage inside the tunnel. But the company decided it was not worth fixing. This was because not many trains used the line. The railroad had not expanded much beyond Gunnison on the west side.

So, the Gunnison Division of the Colorado & Southern was closed. It stopped running from St. Elmo on the east side of the pass. It also stopped running to Quartz on the west side. Some parts of the line were traded with the Denver & Rio Grande Western railroad.

The Alpine Tunnel Today

The east entrance of the tunnel has fallen in. The west entrance is covered by landslides. The old railbed on the east side is now a hiking trail. On the west side, a rough road follows the old railbed. This road leads to a restored train station.

Not much is left of the station complex. The railroad built it to help trains and workers in this remote area. But volunteers have worked hard to restore parts of it. They have fixed the railroad's 1883 Alpine Tunnel telegraph office. They also rebuilt the station platform. They even put back 120 feet (37 m) of rail track, a turntable, and an outhouse.

Only ruins remain of the section house and engine house. Other buildings and railroad structures have disappeared. Volunteers still work on restoring the complex at least once a year.

The Alpine Tunnel Historic District was added to the National Register of Historic Places in April 1996. This means it is a special place recognized for its history. It is usually open for visitors from July to September.

Gallery

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  Alpine Tunnel telegraph station

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  Western Portal

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  Eastern Portal

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  Palisades west of Alpine Tunnel