



Discover everything you want to know about the Gateway Arch with these frequently and not so frequently asked questions!


Why was the Gateway Arch built?
The structure was built as a monument to the vision of Thomas Jefferson and St. Louis’ role in the westward expansion of the United States.

Why is the National Park called the “Jefferson National Expansion Memorial”?
It is a memorial to President Thomas Jefferson, who championed the Louisiana Purchase and sent Lewis and Clark on their expedition westward.

How tall is the Gateway Arch?
630 feet, which is 63 stories, 192 meters, or 7560 inches tall

How wide is the Gateway Arch?
The span is 630 feet at ground level between the outer sides of the legs.

How wide are the legs at the base?
54 feet

How wide is the top?
17 feet

How many stainless steel sections are there?

How deep are the foundations?
About 60 feet deep

How much does the Gateway Arch weigh?

43,226 tons

What is the Gateway Arch made out of?
Steel and concrete. Double wall construction with 1/4” stainless steel on the outside and 3/8” structural steel on the inside. The distance between the wall or “skins” at the surface is 3 feet, narrowing to less than 1 foot at the top. There is a layer of concrete between the skins approximately half way up the legs of the Gateway Arch.

Who supplied the steel?
Pittsburgh–Des Moines Steel Company

Who was the architect?
Eero Saarinen won a national competition and the prize of designing the memorial in 1947.

Who was the building contractor?
MacDonald Construction Company of St. Louis was the prime contractor on the Gateway Arch project.

How big are the windows at the top?
7 inches by 27 inches, with 16 windows on each side of the observation deck

Why are the windows so small?
Over 500 tons of pressure was used to pry the north and south legs of the Arch apart for the last four-foot piece to be placed at the top. A larger window would not withstand that pressure.

Does the Arch sit exactly north and south?

No, it's 18 degrees off.

What is the speed of the tram capsules?
340 feet per minute, approximately 3.86 miles per hour

How much did building the Gateway Arch cost?
$13,420,168 for the Arch. The grand total spent for the total area development was $51,300,373 over the course of 30 years. This figure consists of a large amount of non-federal funds and includes the $1,977,750 for the transportation system paid for by the Bi-State Development Agency (Metro Transit).

What shape is the Gateway Arch?
The Arch is a weighted catenary curve. Catenary means it is the shape a free-hanging chain takes when held at both ends.

When was construction of the Gateway Arch started?
February 12, 1963

When was the last piece put into place?
The final steel section of the Gateway Arch was placed on October 28, 1965.

How long have the Arch trams been running?

The north tram was completed first and opened in July 1967, and the south tram opened in May 1968.

When was the Visitor Center opened?
June 1967

When was the Tucker Theater opened?
May 1972

When was the Museum of Westward Expansion opened?
August 1976

How often do the trams go up?
If one tram is running, every 10 minutes. If both trams are running, every 5 minutes.

How many people can the trams take to the top of the Gateway Arch in one hour?
If one tram is running, 240 passengers. If both trams are running, 480 passengers.

How many stairs are there?
1,076 steps

Can guests walk the stairs?
No, the stairs and elevators are used for maintenance and emergencies only.

Does the Arch sway?
The Arch is designed to sway as much as 18 inches, and can withstand an earthquake, however under normal conditions the Arch does not sway. It takes a 50-mile an hour wind to move the top 1.5 inches each side of the center.

How long can we stay at the top?
All visitors are allowed to stay as long as they like. However, the approximate time of a complete trip is 45 minutes (or until closing time).

Do visitors go back down the same side they came up?
If only one tram is operating on a given day, visitors must return on that tram, but if both trams are operating they may return on either side.

What river is that directly below?
The Mississippi River flows directly below the east windows of the Arch at a normal top water speed of 3 miles per hour at a depth of about 12-15 feet. The Missouri River meets the Mississippi River about 15 miles to the north of the Arch.

How big is the viewing area at the top?
The viewing area at the top can hold up to 160 people. There are 16 windows on each side of the viewing area.

Are there restrooms or a snack bar at the top?
There are no facilities at the top of the Arch.

How far can you see in either direction at the top?
On a clear day, the view at the top can extend up to thirty miles in either direction. However, St. Louis can be a very hazy city, which reduces visibility at the top. On cool, damp mornings, a dense fog can create zero visibility at the top.

Which side is Missouri and which is Illinois?
The Missouri side of the river is to the west and includes downtown St. Louis. The Illinois side of the river is to the east and includes the vast industrial complexes of East St. Louis.

How large is the Memorial and does the Memorial consist of more than the Gateway Arch?
The entire Memorial is about 91 acres. This includes the Gateway Arch and grounds (about 62 acres), plus another 30 acres or so encompassing the Old Courthouse, Luther Ely Smith Square and a good bit of the surrounding streets (managed as easements).

Why does the memorial consist of more than just the Arch?
Jefferson National Expansion Memorial was envisioned, from the time it was proposed by civic leaders in the 1930s, as being a commemorative site that would interpret St. Louis’ role in the westward expansion of the United States. Over the years, several different proposals were put forward to accomplish this goal, all of which utilized the entire landscape of a large, rectangular area roughly corresponding with the original site of the French colonial town of St. Louis. Eero Saarinen’s vision of the site, which was judged the winner of the 1947–1948 architectural competition, also encompassed the entire area. All 172 entrants in the competition had to create a landscape design as well as “a large, central feature,” and most retained landscape architects on their design teams to ensure that they created a holistic space within the 62 plus acres of the site, and not just a spectacular centerpiece. The seven-person competition jury that chose the Saarinen design purposely included a landscape architect, S. Herbert Hare, for just this reason. The centerpiece of Saarinen’s design, the magnificent Gateway Arch, so enthralled the competition judges (and all later viewers) that it not only dominated the site but made people forget that a specific landscape was also designed to correspond with and enhance the Arch. Jefferson National Expansion Memorial is the entire site, and not just the Gateway Arch.

Does the National Historic Landmark Nomination refer to both the Gateway Arch and the grounds which surround it?
Yes. Sixty-two acres of Jefferson National Expansion Memorial, including the Gateway Arch structure and the surrounding landscape, was designated a National Historic Landmark in 1987. Although most people realize that the Gateway Arch stands with the Statue of Liberty, the Golden Gate Bridge, Mt. Rushmore and the Washington Monument as universally recognizable forms and symbols of national identity, few are aware of the significance of the landscape which surrounds it. Architect Eero Saarinen and landscape architect Dan Kiley planned a landscape for the Arch, which complements, enhances and echoes the graceful lines of the structure, while not calling attention to it. The National Historic Landmark designation included not only the “massive stainless steel structure” of the Arch itself but also the “curvilinear, graceful staircases of toned concrete at the north and south ends [which] provide access to the grounds from the riverfront. The grounds themselves are carefully landscaped with ponds, trees and walkways that again reflect the gentle curve of the Arch. Similar curves are repeated in the tunnel entrances for the railroad tracks that cut through the property.” The scale, impact and design of the grounds constitute an essential mooring for the world-famous Arch and merge the Arch and its grounds, with one reflecting the other.

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