The Toronto Zoo has received a $2 million donation Thursday, the largest single donation in its nearly 40-year history.

The donation came from the estate of Mary Millard, who passed away last year. Millard was a naturalist who loved plants and animals. Her home in Hogg’s Hollow was her pride and joy, and she maintained it in a natural state.

“This wonderful gift will ensure Mary’s legacy will make a difference for future generations connecting to wildlife and nature at the Toronto Zoo,” said Gloria Luby, vice-chair of the zoo’s board of management.

Millard attended Havergal Collegeand she graduated from the University of Toronto, where she studied philosophy and sociology.

She then worked briefly as a high school teacher.

Millard, who died in May 2013 at 87, was predeceased by her husband and had no children.