Twentieth century America built the Gateway Arch as a monument to the westward expansion of the United States. Twenty-first century America allows the Gateway Arch to rust and corrode, apparently as a metaphor for our global standing and fiscal health.

Almost 45 years into its reign atop the St. Louis skyline, the 630-foot monument is suffering from growing rust and decay. And nobody knows how extensive.

Corrosion, some of it feared aggressive, and severe discoloration of the stainless steel skin have long been present, according to engineering reports reviewed by the Post-Dispatch.

The documents and interviews with metallurgists indicate that the remedy could be as minor as an “expensive” surface cleaning or as elaborate as a full-blown restoration. One report, completed in 2006, called for a deeper study, for which the National Park Service says it only recently obtained funding…

The problems are increasingly evident, with streaks and spots marking the upper reaches of the Arch exterior.

The 2006 report found rusting bolt heads and internal steel, corroding staircases, and a leaking interior. Never mind a “mysterious staining of the glimmering surface”, which sounds…troubling.

Despite four years having passed since the report was released, no repair work has been conducted or even planned. Which means the problem has likely only gotten worse. That might help explain why the city is now hiding the condition of the Arch from the media:

A Post-Dispatch reporter was allowed to review the corrosion report for about 40 minutes earlier this month. But officials refused to make it available for a second look the next day, citing national security concerns and saying it should not have been provided the first time.

National security concerns. A guided tour of the Gateway Arch for a credentialed reporter qualifies as a threat to national security? What, is the Missouri branch of NORAD located in the Arch? No? Then it sounds like officials are trying to hide the problem from the media.

According to the Post-Dispatch report, the Arch hasn’t been cleaned completely since 1965. And the superintendent of the monument says there’s no plan to rectify that problem in the future.