Renovated Arch museum debuts, McCarthy Building Companies was general contractor

A 47,000-square-foot subterranean expansion and renovation of the Museum of the Gateway Arch, constructed by McCarthy Building Companies Inc., is the final component of a $380 million redevelopment of the iconic monument in downtown St. Louis.

As a primary general contractor of the Gateway Arch Park redevelopment, McCarthy also oversaw the transformation of the north and south grounds surrounding the 50-year-old national historic landmark.

The renovated museum and visitors center opened to the public Tuesday, July 3. It is designed to enhance the overall experience for the 4 million individuals who visit the 630-foot-tall structure, on average, each year. A dramatic new circular entrance and upper-level lobby facing downtown St. Louis replaces the previous underground entrances at the base of each Arch leg. Visitors will now enter the monument at street level, through a custom-built glass and stainless-steel entry enclosure system.

The expanded museum’s reinforced roof deck features 2,400 cubic yards of post-tensioned concrete slabs, as well as 189,000 cubic feet of GeoFoam blocks, an innovative solution to eliminate additional excessive weight on the roof deck.

“This highly complex project involved close coordination among multiple layers of consultants, architects, archaeologists, governmental agencies and subcontractors all working together to bring it to life,” said Ryan Freeman, McCarthy vice president of operations.

Constraints on all four sides limited access points and the ability to transport materials to the monument, which is situated at the center of a 70-acre site. To the east is the Mississippi River, the region’s foremost waterway (and the source of two flood events that significantly impacted construction activities). And to the west is a major interstate highway that bisects the Arch from the densely occupied downtown area.

Further complicating this scenario, the Gateway Arch had to remain open, accessible and fully operational throughout the three-year construction project.
The museum’s grand mezzanine features a colorful terrazzo floor with a giant U.S. map illustrating the westward migration from St. Louis and other cities. It leads to several new galleries that trace St. Louis’ role in westward expansion from the mid-1600s to the present. A 100-foot video wall inside the tram lobby projects scenes from the original construction of the Gateway Arch and other examples of American innovation. The entrance, building and exhibits are designed to meet universal design standards so the museum can be accessible by all individuals regardless of age, size, ability or disability.

Designed and constructed to pursue LEED Silver certification from the U.S. Green Building Council, the expansion is the facility’s first renovation since the original Museum of Westward Expansion opened in 1976.

The museum expansion was designed by Cooper Robertson and James Carpenter Associates, both of New York, with Trivers Associates, St. Louis. Michael Van Valkenburgh Associates, New York, oversaw the landscape design.

Gateway Arch Park Foundation and the National Park Service led the Gateway Arch Park redevelopment projects.