COMMUNITY PLANNING AND DEVELOPMENT MEMO REPORT OF FINDINGS FOR CERTIFICATE OF DEMOLITION ELIGIBILITY - City and ...

Community Planning and Development
                                                                          Denver Landmark Preservation

                                                                             201 West Colfax, Dept. 205
                                                                                    Denver, CO 80202
                                                                                      p: 720.865.2709
                                                                                       f: 720.865.3050
                                                                         www.denvergov.org/preservation

     COMMUNITY PLANNING AND DEVELOPMENT MEMO REPORT
     OF FINDINGS FOR CERTIFICATE OF DEMOLITION ELIGIBILITY

December 15, 2020
Address: 2450 Curtis Street
Legal Description: L 1 TO 5 INC BLK 116 TAPPANS ADD
Current Building Name: Greyhound Bus Lines
Construction Date: c.1945
Source of Information: Denver Assessor’s Office; Sanborn Insurance Maps from 1904, 1904
(corrected to 1925), 1929-30, 1929 (corrected to 1937), 1929 (corrected to 1951), 1929
(corrected to 1956), 1929 (corrected to 1958), 1929 (corrected to 1961), 1962 (corrected to
1967); Denver Post.
Architectural
Architectural Style: Industrial
Architect/Builder: unknown
Source of Information: n/a
Historical
Original owner: Cummins Diesel Sales of Colorado
Original use(s): diesel engine service and sales
Current use(s): vacant

Historical background:
The two-story brick industrial building at 2450 Curtis St. was constructed c. 1947 by Cummins
Diesel Sales of Colorado, a subsidiary of Cummins Diesel Engine Co. of Columbus, Indiana.
Established in 1919, the company had become a leader in diesel engine production and
innovation by the 1940s. The company’s first major commercial engine, the Model F, was
offered through the Sears, Roebuck Company catalog in the 1920s. In 1931, Cummins debuted
a diesel engine at the Indianapolis 500 that was fuel-efficient enough to run the entire race
without a single pit stop. The Cummins racecar finished 13th out of 33 cars. Over the next
couple decades, Cummins would continue to develop diesel engines for race cars as they
experimented with ways to increase the speed and efficiency of their engines. During World War
II, with diesel engines in high demand, Cummins providing diesel engines to the U.S. military.
This included diesel engines for naval ships' electrical service generators, heavy duty trucks,
and stationary land-based generators. Cummins grew to meet the demand, expanding its
facilities, increasing its labor force, and offering an expanded range of engines. In 1947,

Cummins stock was publicly traded for the first time. The Cummins N series engines became
the industry leader in the post-World War II road building boom in the United States as the new
highway system created opportunities for interstate trucking. Cummins produced more than half
the heavy-duty truck engines in the U.S. in the 1950s.
Cummins appears to have established its first sales and service location in Colorado in 1942,
pulling a building permit for the conversion of a garage at 2501 Champa St. into a motor vehicle
repair shop. Cummins quickly outgrew this facility, purchasing lots 1-6 of Block 116 in 1946 for
the construction of a new Denver headquarters. The new facility appears to have been
completed by 1947 when an advertisement seeking experienced mechanics to work at
Cummins Diesel Sales of Colorado at 2450 Curtis St. appeared in the Denver Post. The
spacious new building extended across five lots (1-5). The two-story structure was brick with
large steel factory windows and a monitor roof to provide additional light and ventilation to the
interior.
In 1950, a Denver Post article described a new engine demonstrated at the headquarters for
350 Denver area customers. According to Cummins, the new engine was “the most
revolutionary engine since the jet” engine. The new diesel engine was the lightweight, high-
speed model JS-600 with a rating of 150 horsepower at 2,500 rpm. Without clutch and
transmission, the engine weighed 840 pounds and was versatile enough to be installed in trucks
with a gross weight, including load, from two to twenty-five tons. The new engine was the
culmination of more than two years of research and had been tested at the Indianapolis
speedway. According to Cummins: “The same engine used in the racing cars is adaptable for
use in trucks. It is guaranteed to perform faultlessly for 100,000 miles for one year. . . . Truck
operators are clamoring for it, and thousands will soon be installed in Ford, Chevrolet and
General Motors trucks.” Cummins continued to work to perfect its engine, setting a new
Indianapolis speedway lap speed record in 1952. Said Cummins, “This sleek speedster was
designed to discover new ways to build more powerful, more efficient engines to meet
economically the heavy-duty power needs of all industry. It is another milestone in the Cummins
program of practical research with a commercial future, and it will result in more dependable
performance wherever lightweight, high-speed diesel power is applied.”
By 1959, the Cummins headquarters at 2450 Curtis St. employed 90 persons with 10 more at a
branch in Casper, Wyoming. The Denver operation included truck repair and engine rebuilding
facilities as well as a 24-hour emergency service fleet to assist truck owners anywhere in the
Rocky Mountain states. Local advertisements declared that Cummins provided “power for every
need,” including trucking, construction, industrial, petroleum, and farming. In Colorado,
Cummins also worked to develop diesel engines optimized for performance at high altitudes,
providing a custom-built engine to the National Park Service in 1960 that were designed to
provide light and power for a park lodge above 9,000 ft. in Rocky Mountain National Park. The
same year they also provided contractor H-E Lowdermilk Co. (responsible for earthmoving,
mountain pass construction, and highway projects throughout New Mexico, Arizona, Utah, and
Colorado in the mid-20th century) with the region’s first V-8 turbo diesel engines designed for
high altitude work.
In 1962, Cummins decided that they had outgrown this location. 2450 Curtis was put up for sale
as Cummins constructed a new 34,000 sf building at 58th and Fairfax. The new facility would be
the second largest Cummins facility in the U.S. According to the Denver Post, Cummins’
business volume had increased more than 400 percent over the past decade, with Cummins

becoming the “major supplier of new and rebuilt engines and spare parts to users of diesel
equipment.”
Continental Trailways acquired 2450 Curtis St. for use as their office headquarters and bus
maintenance and storage facility. They also acquired the machine shop at 2420-2424 Curtis St.
and pulled a building permit for the construction of an addition to connect 2450 Curtis St. to the
machine ship at 2420-2424 Curtis St. Continental Trailways was part of the National Trailways
Bus System established in 1936 to compete with Greyhound Bus Lines. It was the first
organization to support and promote small bus companies working together to benefit from
name recognition and through shared ticketing and scheduling. Both the Greyhound and
Trailways route networks evolved from what originally were many small bus companies, which
were gradually consolidated into the two nationwide intercity bus systems.
Trailways also sold used buses from this location. The company replaced their buses
approximately every 12 years, using the maintenance facility to refurbish them before reselling
them. The regional sales lot here drew customers from a 1,000-mile radius since the next
closest sales lots were in California and Georgia. Bus buyers included bands, schools, and
individuals seeking to convert them to recreational use.
In 1987, Greyhound bought out Trailways and the property at 2450 Curtis Street became used
to service and maintain Greyhound buses. This service location was convenient to the
Greyhound bus terminal at 1055 19th St. in downtown Denver. Greyhound moved out of the
downtown bus terminal in 2020, moving operations to Union Station.
Source of Information: Denver Assessor’s Office; Sanborn Insurance Maps from 1904, 1904
(corrected to 1925), 1929-30, 1929 (corrected to 1937), 1929 (corrected to 1951), 1929
(corrected to 1956), 1929 (corrected to 1958), 1929 (corrected to 1961), 1962 (corrected to
1967); Denver City Directories; Denver Post; www.cummins.com

Designation Eligibility Assessment

Landmark Designation Criteria:
A structure or district may be designated for preservation if, due to its significance, it meets the criteria
listed in subsections (1), (2), and (3) below

(1) The structure or district maintains it integrity;

(2) The structure or district is more than 30 years old, or is of exceptional importance; and

(3) The structure or district meets at least 3 of the following 10 criteria:

        ☒It has a direct association with a significant historic event or with the historical development
          of the city, state, or nation;

        ☐It has direct and substantial association with a recognized person or group of persons who
          had influence on society;

☒It embodies the distinctive visible characteristics of an architectural style or type;

       ☐It is a significant example of the work of a recognized architect or master builder;

       ☐It contains elements of design, engineering, materials, craftsmanship, or artistic merit which
         represent a significant innovation or technical achievement;

       ☒It represents an established and familiar feature of the neighborhood, community or
         contemporary city, due to its prominent location or physical characteristics;

       ☒It promotes understanding and appreciation of the urban environment by means of
         distinctive physical characteristics or rarity;

       ☐It represents an era of culture or heritage that allows an understanding of how the site was
         used by past generations;

       ☐It is a physical attribute of a neighborhood, community, or the city that is a source of pride or
         cultural understanding;

       ☐It is associated with social movements, institutions, or patterns of growth or change that
         contributed significantly to the culture of the neighborhood, community, city, state, or
         nation.

Integrity: If a structure maintains its integrity, it may be designated for preservation.

☒ Has integrity
☐Does not have integrity

Does the structure have potential for designation?

☒Has potential for designation
☐Does not have potential for designation

2450 Curtis Street is significant for its association with the post-World War II economic growth of
Denver and more specifically with the local development of the transportation industry.
Constructed by Cummins Diesel Engine Co. c.1947, the building is associated with the
transportation industry through the diesel engines produced, sold, and serviced here from
c.1947 until 1962. Cummins was a major supplier of diesel engines for the trucking industry
which was expanding at midcentury along with the interstate highway network. Cummins also
designed engines specifically for use at high altitude. Cummins was a major supplier of diesel
engines for the military, especially during World War II and the Korean War, tying it to the 20th
century development of the defense industry in Colorado. After Cummins moved to a larger
facility, 2450 Curtis Street became the Denver headquarters and bus maintenance facility for
Continental Trailways, continuing the building’s association with the transportation industry. In
the 1970s, Continental Trailways bus routes served 92 percent of cities and towns in Colorado.

2450 Curtis Street is also significant as a good example of a 1940s industrial building. The two-
story brick building features large, multi-light steel factory windows. The flat roof is topped by a
large monitor roof with clerestory windows to provide light and ventilation to the building interior.
While the overall design is functional, the building features a distinctive brick pattern with
horizontal bands of red brick connected by vertical strips of buff brick. The building retains a
high degree of integrity with surprisingly few alterations. Most of the windows appear to be
original. Garage doors facing 25th St. have been replaced but the openings appear historic. The
adjacent addition on lots 6-9 is simple in design and has very limited visual impact on the
original structure.
2450 Curtis also has significance as an established and familiar feature of the Curtis Park
neighborhood due to its large scale and prominent location at the corner of Curtis Street and
25th Street. The large brick structure extends across five lots and is topped by a distinctive
monitor roof.
Finally, 2450 Curtis has significance for its potential to promote the understanding and
appreciation of the urban environment as an increasingly rare example of the mid-20th century
industrial and commercial history of this area. This area has undergone extensive
redevelopment in recent years, leaving limited evidence of this industrial past. Sanborn maps
show that in 1890 this block and the adjacent block were filled with single-family residences and
row homes. But by the 1920s, this was shifting, with single-family homes converted to multi-
family dwellings and many older homes demolished for new industrial uses. Block 116 included
an industrial laundry facility and the adjacent block was home to the A.E. Meek Trunk & Bag
Factory as well as another laundry. By 1945, this area was being advertise as a “Commercial
Zone” with a real estate advertisement in the Denver Post promoting the intersection of Curtis
and 25th as “right in the nest of such concerns as Gallagher Transportation Co., Ideal Laundry,
Cummins Diesel Engine CO., and Atlas Luggage.” By the mid-1950s, nearby businesses
included a machine shop, Goodwill warehouse, transfer company, tires sales, furniture,
plumbing and heating, auto sales, auto wrecking, and wholesale groceries.