Editing Gateway Arch (section)

===Visitor center===
[[File:Gateway Arch visitors center.jpg|thumb|right |Inside the visitor center prior to its 2018 renovation]]
The underground visitor center for the arch was designed as part of the National Park Service's [[Mission 66]] program.<ref>{{cite book |chapter-url=http://www.nps.gov/history/history/online_books/allaback/vci.htm |title=Mission 66 Visitor Centers: The History of a Building Type |last=Allaback |first=Sara |chapter=Appendix I: Mission 66 Visitor Centers |year=2000 |publisher=National Park Service |isbn=978-0-16-050446-4 }}</ref> The {{convert|70000|ft2|m2|adj=on}} center is located directly below the arch,<ref name="Kimbell">{{cite news |url=https://pqasb.pqarchiver.com/enquirer/access/1822812391.html?FMT=ABS&FMTS=ABS:FT |title=Enter the Gateway of St. Louis |last=Kimbell |first=Becky Yaeger |date=October 12, 2003 |newspaper=[[The Cincinnati Enquirer]] |page=T.2 |access-date=January 13, 2011 |archive-date=November 5, 2012 |archive-url=https://web.archive.org/web/20121105083509/http://pqasb.pqarchiver.com/enquirer/access/1822812391.html?FMT=ABS&FMTS=ABS:FT |url-status=dead }}</ref> between its legs. Although construction on the visitor center began at the same time as construction for the arch itself, it did not conclude until 1976 because of insufficient funding;<ref name="Visitor center" /> however, the center opened with several exhibits on June 10, 1967.<ref name="Arch timeline" /> Access to the visitor center is provided through ramps adjacent to each leg of the arch.<ref name="Visitor center">{{cite book |url=https://books.google.com/books?id=4zuo4E6WLKwC&pg=PA121 |title=Underground Buildings: More Than Meets the Eye |last=Hall |first=Loretta |publisher=Quill Driver Books |year=2004 |page=121 |isbn=978-1-884956-27-0 }}</ref>

The center houses offices, [[mechanical room]]s, and waiting areas for the arch trams, as well as its main attractions: the [[Museum of Westward Expansion]] and two theaters displaying films about the arch.<ref name="Visitor center" /> The older theater opened in May 1972;<ref name="Arch timeline" /> the newer theater, called the Odyssey Theatre, was constructed in the 1990s and features a four-story-tall screen. Its construction required the expansion of the underground complex, and workers had to excavate solid rock while keeping the disruption to a minimum so the museum could remain open.<ref name="Visitor center" /> The museum houses several hundred exhibits about the United States' [[westward expansion]] in the 19th century<ref name="PopSci" /> and opened on August 10, 1977.<ref name="Arch timeline" />

As part of the CityArchRiver project, the visitor center and museum underwent a $176 million expansion and renovation that was completed in July 2018.<ref name="Hahn">{{Cite news |url=https://www.stltoday.com/entertainment/arts-and-theatre/hotlist/gateway-arch-museum-visitors-center-to-open-in-time-for/article_9222e6c1-b789-54ac-93af-241ea9abeccd.html |title=Gateway Arch museum, visitors center to open in time for Fair St. Louis |last=Hahn |first=Valerie Schremp |work=stltoday.com |access-date=December 14, 2017 |language=en }}</ref> The renovation includes a 46,000-square-foot underground addition featuring interactive story galleries, video walls, a fountain and a cafe.<ref name="Hahn"/>