In 2018, the Society donated the last installment of five $100,000 gifts pledged to the park to be used specifically for sculpture preservation at Mount Rushmore National Memorial. The funds were a result of an initial $214,000 bequest from the Betty Nelson, Yankton, SD, estate. The Society contributed an additional $200,000 and managed the fund for its ultimate donation to the National Park Service.

The National Park Service uses these funds to support the Ropes Team that inspects the Memorial on an annual basis and to support the Rock Block Monitoring System. The Rock Block Monitoring System was first put in place more than 20 years ago to monitor changes within the sculpture due to weather and time.

Sculpture preservation efforts like these are ongoing.