Completed in 1929, the Telephone Building at 931 14th Street in Denver served for fifty-five years as the headquarters of Mountain States Telephone and Telegraph. Designed by architect William N. Bowman in a combination of Art Deco and Gothic Revival styles, the building helped bring modern architecture to Denver. Since 1984 the building has been home to various Mountain States successors, such as U S West, Qwest, and CenturyLink.

Galvanic Muttering Machines

The Denver Telephone Dispatch Company started the city’s first telephone service in 1879, three years after Alexander Graham Bell patented the device. One newspaper headline declared, “The New System of Galvanic Muttering Machines in Operation.” The service, which was the first commercial exchange between the Mississippi River Valley and the West Coast, started with 162 customers.

Soon new exchanges and small telephone companies sprouted up throughout the Rocky Mountains. In 1911 Mountain States Telephone and Telegraph was created as a result of a reorganization within American Telephone and Telegraph (AT&T) and mergers between companies covering the Rocky Mountain region from Idaho and Montana to Arizona and New Mexico. At the time, the company served more than 160,000 phones, and it completed the first long-distance line between New York and Denver. The next year another long-distance line stretched from Denver to San Francisco.

Phone service in the Mountain States region grew quickly over the next two decades, tripling to nearly 500,000 phones by 1930. By the middle of the 1920s, it was already clear that the company would need more space to house its growing administrative staff. Moreover, the company planned to introduce dial service in Denver to automate local calls without the need for operators. Dial service required switches whose size and weight made them impossible to house in any existing building. To accommodate its staff and switches, Mountain States decided to build a large custom-designed headquarters in Denver.

New Headquarters

Design of the new headquarters building, commonly known as the Telephone Building, began in 1926. Local Bell engineers made sure the framework fit the company’s technical requirements, and Denver architect William Bowman devised the building’s exterior. Mountain States chose a location at the corner of 14th and Curtis Streets, not far from its existing headquarters on Champa Street, and construction began in March 1927.

The building was largely a Colorado production. In addition to local architect Bowman, it featured 4,000 tons of steel from Pueblo and Denver, more than 2 million bricks from Golden and Denver, travertine from nearby Salida, pink granite from Platte Canyon, and 1,800 tons of terra cotta made in Denver, as well as the handiwork of local craftsmen responsible for lighting fixtures and other design elements. The building itself cost $3 million, plus an additional $2 million for the furnishings and switching equipment, and was completed in 1929, the fiftieth anniversary of the start of telephone service in Denver.

The architectural style Bowman used for the building, which Mountain States called “Modern American Perpendicular Gothic,” was based on Neo-Gothic skyscrapers such as New York’s Woolworth Building (1913) as well as on the New York Telephone Company’s new Art Deco headquarters then under construction, the Barclay-Vesey Building (1927). Rising ten stories and then stepping back twenty feet to a five-story central tower with Gothic turrets, the Telephone Building in Denver was the first to take advantage of a setback provision in the city height ordinance that allowed buildings to rise above twelve stories if their additional height was set back from the street. Topping out at nearly 237 feet, the building was the tallest in Denver (aside from smelter stacks and the Daniels and Fisher Tower) until the 1950s and contained about 5.2 million cubic feet of space.

The Telephone Building’s interior made it one of the most lavish commercial buildings in Denver. The main lobby featured buff-colored travertine walls, marble floors and baseboards, and walnut woodwork. Some of the interior design was influenced by the Colorado artist Allen True, who also painted thirteen murals for the building’s entrances and lobbies depicting events and themes from the history of communications (“The Smoke Signal,” “The Pony Express,” “The Switchboard Operator”). The murals are considered some of True’s best work.

Most floors from the second to the fifteenth held offices, with the executives on the fourteenth floor. Long-distance equipment occupied the fourth floor, and long-distance switchboard operators sat one floor above. The second floor was special because it held the new switches that would allow direct local dialing in Denver. Each switch weighed twenty-two pounds, six switches were required to make a single call, and the system was designed to accommodate 40,000 simultaneous calls, meaning the second floor had to hold 240,000 switches weighing more than 2,600 tons. To hold the equipment, it was designed with sixteen-foot ceilings and extra-thick floors made of concrete and steel.

Denver’s local telephone service switched over to the new equipment on May 4, 1929. The building was fully occupied by its 1,510 workers by the end of July, and it officially opened to the public August 6–8 in a grand-opening ceremony that attracted more than 20,000 visitors. After it opened, about 45,000 Denver residents came to the Curtis Street entrance each month to pay their telephone bills, passing True’s “Smoke Signal” and “Pony Express” murals along the way. The building quickly became a landmark in the Denver skyline, especially at night, when its upper stories were illuminated by forty-eight floodlights on the terraces. The floodlights were turned off during World War II.

Expansions, Breakups, and Acquisitions

Telephone service increased rapidly in the decades after World War II, requiring Mountain States to expand its headquarters. In the late 1940s the company added on to a five-story light well on the south side of the building to house more offices and long-distance switchboards. A two-story addition along Curtis Street followed in 1958–59, using the same materials and design as the original building.

In the early 1960s Mountain States built a five-story International-style building that was directly east of the Telephone Building and connected to it by internal passageways. Almost as soon as this building was completed, in the mid-1960s, the company added seven more stories to it. Even these rapid additions around the original Telephone Building could not keep pace with the company’s growth. In the 1970s Mountain States began to build new skyscrapers elsewhere in Denver, such as 1005 17th Street, to house some of its operations.

After fifty-five years in the Telephone Building, Mountain States moved its headquarters to 1801 California Street in 1984, the same year that it was transformed into a new company called U S West as a result of the breakup of AT&T. Since then, the Telephone Building on 14th Street has continued to be owned and used by U S West and its Denver telecommunications successors, Qwest and CenturyLink. The building’s Allen True murals were restored in the 1980s and cleaned again in the 2000s. Renovated in 2009–10 to accommodate more workers, the building continues to serve as the main central office in Denver, provide dial tone and other services for the whole state, and distribute calls to other central offices across the country and the world.