The railroad opened up the first rail routes to a large section of the central Colorado mining district in the decades of the mineral boom.

Founded in 1872 by Colorado Governor John Evans, the company was purchased by the Union Pacific Railway in 1880, though it continued to be operated independently.

[2] When the Union Pacific went bankrupt in 1893, the DL&G lines went into receivership and were eventually sold to the Colorado and Southern Railway.

[1] In the first half of the 20th century, nearly all the company's original lines were dismantled or converted into 4 ft 8+1⁄2 in (1,435 mm) standard gauge.

From Como the main line traversed South Park to Garo, where a spur went northward to Fairplay and Alma.

On the western side of the pass, a small spur of the main connected to Buena Vista, then traversed the southern end of the Sawatch Range through the Alpine Tunnel to Pitkin and Gunnison.

A principal branch of the main line north from Como went over Boreas Pass to Breckenridge, Dillon, Keystone, Frisco and Climax.

The company was incorporated in the Colorado Territory as the "Denver, South Park and Pacific Railway" on October 2, 1872, with 2.5 million dollars in capital.

Less than a year later, on June 16, 1873, it was reorganized by John Evans as the "Denver, South Park and Pacific Railroad" with an increased capitalization of 3.5 million dollars.

The original stone roundhouse at Como has been restored, and is presently in use in the operation of a 3’ narrow gauge locomotive acquired from the Klondike gold fields.

In November 1879, with the tracks only as far as South Park, the company contracted for the initial construction of the Alpine Tunnel, with an expected finish date of July 1, 1880.

The Denver, South Park, & Pacific built north of Gunnison up the Ohio Creek Drainage to the Castelton and Baldwin Areas.

On July 17, 1889, the company was sold at foreclosure proceedings to the Denver, Leadville and Gunnison Railway, a new railroad which was formed to operate the DSP&P lines.

These locomotives were most often used to haul daily passenger trains from Denver to the South Park region of Colorado on account of their low tractive effort.

The Denver, South Park & Pacific owned nineteen 2-6-6T and four 2-8-6T type locomotives built by the Mason Machine Works.

Another distinct feature of locomotives of this time period were bright and decorative Russia Iron boiler jackets, though these were eventually either replaced or completely painted over.

Common spark arrestors to see on the early years of the South Park Line were the "Nesmith" and "Congdon" designs.

In the years that the Colorado & Southern controlled the South Park's railway network, a common spark arrestor that could be seen after 1917 was the "Ridgway" design.

As of 2020, #9 is on static display at the Rotary Snowplow Park in Breckenridge, Colorado, having suffered mechanical damage while in service at the Georgetown Loop in 2006.

[citation needed] The Como roundhouse locomotive (Klondike Kate #4) is a 1912 2-6-2 by Baldwin Locomotive Works manufactured for the Klondike Mines Railway, operating to Dawson, Yukon Territory, then after 1942 on the Alaskan White Pass & Yukon, before operating on tourist lines in the Lower 48 states of the USA.

It also is not a historic DSP&PRR locomotive, having waited until 2017 to run on South Park track, in the Como, Colorado and Boreas Pass area.

[citation needed] Mason Bogie "Tenmile" after Union Pacific re-lettering DSP&P Cooke 2-6-0 information