As of 2014,[update] the zoo was middle Tennessee's top paid attraction and contained 3,736 individual animals, encompassing 352 species.

Margaret and Elise Croft, the great-great granddaughters of Michael Dunn, the original owner, were the last of the family to live at this location.

[9][10] In 1989, archaeologists evaluating the property for its archaeological resources discovered an unmarked cemetery fairly close to Grassmere's entrance off of Nolensville Road.

It was only in 2013 when a newer entry plaza was planned did the zoo petition to have the bodies exhumed and their remains moved closer to the historic Dunn house by the state archaeologist.

'[10][15] After Elise's death in 1985,[16] the museum began work on this nature study center, calling it Grassmere Wildlife Park.