Patten donated the casts she made to the Guatemalan government as well as her time and expertise. When the 1976 Guatemala earthquake occurred, many of the ancient monuments housed in museums were broken. Joan was called in and asked if she could help restore the monuments. She gladly accepted the offer and was able to make molds of the stelae broken parts. These pieces were then fitted together into a new mold that was later fashioned to make an unbroken replica. Through the years, the Guatemala Museum of History and Anthropology received seventy of Patten's reproductions and the Popol Vuh Museum received approximately fifteen sculptures. Today, many of these casts are on display along a garden pathway within Francisco Marroquín University adjoining the Popol Vuh Museum.