Yerkes Observatory
Williams Bay, WI
Yerkes Observatory
Williams Bay, Wisconsin
United States

Yerkes Observatory in Williams Bay, WI, features a landscape designed by John Charles Olmsted.  

About Yerkes Observatory 

Located in Williams Bay, Wisconsin, Yerkes Observatory is housed in a remarkable Beaux Arts building by Henry Ives Cobb and situated in a landscape designed by famed landscape architect John Charles Olmsted.  

Yerkes Observatory began in 1892 when George Ellery, a young professor of astrophysics at the then-new University of Chicago, learned of two 40-inch telescope lens blanks collecting dust in a warehouse. He convinced the university to acquire them and secured a blank check from Chicago tycoon Charles Tyson Yerkes to build the observatory of his dreams.  

In 1893, before construction began on the observatory, the tube of the Great Refracting telescope— still the largest in the world of its type, even today— was exhibited at the 1893 Columbian Exposition in Chicago, where Frederick Law Olmsted designed the grounds.   

The observatory— housing not only a telescope but also laboratories, workshops and libraries— first opened its dome to the night sky in 1897 and employed or welcomed many of the greats of astronomy and physics, including Otto Struve, Edward Barnard, Gerard Kuiper, Edwin Hubble, Nancy Grace Roman, Carl Sagan and even Albert Einstein.   

The University of Chicago closed the observatory in 2018. In 2020, the University of Chicago transferred Yerkes Observatory and its 50-acre grounds to Yerkes Future Foundation. After completing the first phase of a multimillion-dollar, “brick by brick, tree by tree” restoration project, the foundation reopened the observatory to the public on May 27, 2022, as part of the Olmsted 200 bicentennial celebration. In addition to restoring the building, Yerkes Future Foundation is working to renew the landscape, which includes some of the original trees from the Olmsted design.  

The next chapter for Yerkes includes reinvigorating the observatory as a site for ongoing astronomic research and collaborations, as well as a site for innovative art, culture and public science programs. These efforts— along with two world-class astronomers that Yerkes Future Foundation brought on in 2023— enliven and advance the legacy of discovery and big ideas that made Yerkes Observatory one of the most important sites in the history of global astronomy for modern audiences. 


    Original plan for the Yerkes Observatory grounds designed by Olmsted Brothers, 1906.

    1895 photo by Evelina Hale. Courtesy University of Chicago/Yerkes Observatory.

    Aerial view of Yerkes Observatory by Yerkes Future Foundation.

    Furniture maker turned optical designer George Willis Ritchey uses the Great Refractor. Courtesy University of Chicago/Yerkes Observatory.

    Courtesy University of Chicago/Yerkes Observatory


Washington Park

Originally called West Park, Washington Park in Milwaukee was designed by Olmsted, Olmsted & Eliot beginning in 1891-92.


Olmsted helped lay the groundwork for the protection of Yosemite.