The University of Chicago

373 W. Geneva St, Williams Bay WI 53191 (Latitude 42 34.2, Longitude -88 33.4)
Dome structure

The birthplace of modern astrophysics
Yerkes Observatory is a facility of the Department of Astronomy and Astrophysics of the University of Chicago. It was established in 1897 on Geneva Lake in Williams Bay, Wisconsin. Until the mid-1960's, Yerkes Observatory housed all of the Department's activities. Today the 77-acre, park-like site in southeast Wisconsin provides laboratory space and access to telescopes for research and instruction.
Yerkes Observatory occupies a unique niche for the educational and the scientific community. It bridges several important perspectives in formal and informal education. The history of astronomy and astrophysics of the observatory is a solid foundation for introducing all the important topics in current research as well as the practice of observational astronomy. There is a huge range of opportunities for learning. Because of Yerkes' historical context, the world of professional and student astronomers and astronomy educators is drawn to the observatory. These communities learn from one another, build relationships, and create programs, which result in enriched experiences and learning opportunities for young and diverse members of our society.

Yerkes Observatory is open for free public tours  every Saturday throughout the year. We also offer group tours and special programs.

Upcoming Events

  • Thanksgiving Week Tour Schedule:

    Monday, November 23rd, tours at 11:00 am and 2:00 pm.

    Tuesday, November 24th, one tour at 2:00 pm only.

    Wednesday, November 25th, tours at 10:00 am, 11:00 am and 1:00 pm.
    The Observatory closes at 2:00 pm.

    Thursday, November 26th, the Observatory is closed for Thanksgiving Day.

    Friday, November 27th, tours at 11:00 am, 12:00 pm, 1:00 pm and 2:00 pm.
    The Observatory closes at 3:00 pm.

    Saturday, November 28th, tours at 10:15 am, 11:15 am and 12:15 pm.
    The Observatory closes at 1:30 pm.

  • Regular Saturday Tours
    Yerkes Observatory is open to the public from 9:45 am to 1:30pm every Saturday throughout the year. Guided tours begin at 10:15am, 11:15am and 12:15pm.

    For more information, click here
  • Weekday Tours
    Visitors may tour Yerkes Observatory most weekday mornings or afternoons.

    For types of tours, pricing and more info click here
  • Observe through a Big Telescope
    Throughout the year, weather permitting, Yerkes Observatory offers evening observing sessions for adults and kids aged twelve and up. Participants look at a variety of fascinating celestial objects through a large, modern 24-inch diameter telescope....

    For more inormation, more...

    Give the gift of astronomy to your friends and family this year! Gift certificates valid through December 31, 2016 may be purchased for the Yerkes 24-inch telescope viewing program. Please call 262-245-5555 ext. 825 for more information and to purchase a gift certificate or email

  • Family Night Program
    Yerkes Observatory is continuing a series of Educational Outreach Family Night programs designed for children in grades 3 through 8 along with participating parents or guardians. Programs include fun, hands-on activities for all ages and we can provide an ASL interpreter, if requested...

    To learn more about this event and register, click here

The education programs are made possible in part through SOFIA Outreach at Yerkes Observatory.

University of Chicago Press release: Middle schoolers to explore sky with robotic telescopes

Yerkes Study Group (YSG)
The Yerkes Study Group was formed to explore the best use of Yerkes Observatory as a future site for a regional center for science education. To download the final report (pdf file) of the YSG click here
Yerkes Obs