Jan 22, 2026 15:15:00

What is the artwork of Hoover Dam that depicts approximately 26,000 years of time on a single star map and records the construction date of the dam?

by

Ron Mader

The Hoover Dam , located on the border between Arizona and Nevada, is home to a bronze statue and a mysterious star map sculpture that were erected to commemorate its construction. These sculptures are now facing a crisis.

The 26,000-Year Astronomical Monument Hidden in Plain Sight — LONG NOW IDEAS
https://longnow.org/ideas/the-26000-year-astronomical-monument-hidden-in-plain-sight/

On the western slope of Hoover Dam stands a monument commissioned by the Bureau of Reclamation when construction began on the dam in 1931. The most eye-catching feature in this area, known as 'Monument Plaza,' is a giant bronze winged statue and its central flagpole, which are frequent photo spots for visitors.

At the base of the bronze statue is a marble sculpture known as the 'Star Map,' created alongside the statue by sculptor Oscar J.W. Hansen. The star map accurately plots the dam's completion date based on the Earth's precession , which causes it to tilt on its axis every 13,000 years and then return to its normal position again in another 13,000 years. By comparing the information on the star map with the North Star and other stars, the exact date Franklin Roosevelt dedicated the dam can be pinpointed to within one day.

This star chart was so complex that it required hundreds of thousands of precise astronomical calculations by Hansen, the Smithsonian Institution, and the U.S. Navy. It has been enjoyed by people for 90 years since its installation.

However, in 2022, the star chart will be dismantled as part of a restoration project. Both the bronze statue and the star chart were in need of restoration after years of exposure to the elements, and a contractor commissioned by the Bureau of Reclamation was tasked with repairing both. While the bronze statue only needed painting, the star chart needed to be completely demolished and a new drainage system installed underneath.

The star chart was later dismantled, but an unexpected problem occurred that stalled the restoration project, putting work on hold for over a year.

Aaron Street, a researcher documenting Hansen's history,

started the 'Hoover Dam Star Charts Preservation Project' to raise awareness of the current situation. In 2023, the Bureau of Reclamation's contract was terminated , and it seemed as though restoration might no longer be possible. However, a new contractor was hired in 2024, and work appears to have resumed . However, future restoration plans remain unclear, and Monument Plaza remains hidden from view. It's also unknown where the star charts are currently stored.

'The longer this remains unresolved, the greater the risk that Hansen's important artwork will be lost forever. It is our responsibility to future generations to preserve and restore this masterpiece to its original splendor,' Street said.