how tall is the gateway arch

How tall is the Gateway Arch?

“It stands 630 feet (192 m) tall, and is 630 feet (192 m) wide at its base making it the tallest monument in the United States.”

“The cross-sections of its legs are equilateral triangles, narrowing from 54 feet (16.5 m) per side at the base to 17 feet (5.2 m) at the top. Each wall consists of a stainless steel skin covering a sandwich of two carbon steel walls with reinforced concrete in the middle from ground level to 300 feet (91 m), with carbon steel and rebar from 300 feet (91 m) to the peak. The interior of the Arch is hollow and contains a unique transport system leading to an observation deck at the top. The interior of the Arch also contains two emergency stairwells of 1076 steps each, in the event of a need to evacuate the Arch or if a problem develops with the tram system.”

“The base of each leg at ground level had an engineering tolerance of one sixty-fourth of an inch or the two legs would not meet at the top.”
“During construction, both legs were built up simultaneously. When the time came to connect both legs together at the apex, thermal expansion of the sunward facing south leg prevented it from aligning precisely with the north leg. This alignment problem was solved when the St. Louis Fire Department sprayed the south leg with water from firehoses until it had cooled to the point where it aligned with the north leg.”…..

Gateway Arch

Information on visiting the Arch riverfront