Pierce Engineers (PE) is the masonry and structural engineer on the historic preservation project for Yerkes Observatory, originally constructed in 1897. Though not on the National Register of Historic Places, the observatory contains the world’s largest lens-type telescope, known as the Yerkes “Great Refractor”, used by Einstein and Hubble and has been home to many astronomical discoveries. PE completed a full structural and exterior envelope assessment in the June of 2020. The exterior masonry consists of special roman brick, ornate terra cotta, and of course gargoyles! Each year PE and the masonry contractor work together to develop the prioritized scope to meet the owner’s programming and available budget. As Yerkes finds new life and purpose, with continued astronomical research and new programming opportunities, PE and the full preservation team strive to keep the Yerkes Observatory a beautiful, operational and sustainable facility for the next century and beyond.