The Crazy Horse Memorial Foundation has announced a $10 million matching challenge grant from South Dakota businessman and Giving Pledge signatory T. Denny Sanford.

The gift, which follows a $5 million challenge grant with a dollar-for-dollar match requirement from Sanford in 2007, will fund ongoing efforts to carve a massive sculpture of Crazy Horse in the Black Hills of South Dakota. Designed in the 1940s by sculptor Korczak Ziolkowski at the request of Lakota Chief Henry Standing Bear, the monument is being carved in the round. At 641 feet in length and 563 feet in height, the completed face of Crazy Horse alone is nearly 90 feet tall, while the head of his horse, when completed, will measure 219 feet. Thanks to Sanford's 2007 matching grant, finish work has now begun on Crazy Horse's hand and will continue down through the horse's mane and head.

"Denny is a dear friend and we treasure that most of all," said Ruth Ziolkowski, the sculptor's widow and CEO of the foundation. "His generosity, combined with all the match contributions received from our many friends from throughout the country, is making tremendous difference. It has allowed us to address the many very detailed and costly geo-technical aspects of carving the mountain before additional final-finish work could be done."