Lake Sanford was used as a tailings dump for the titanium mine at Tahawus, which operated from 1940 to 1989, and eventually it was filled in and became a desert of grey sand. The Hudson River was diverted around the impounded tailings and flows through culverts under one of the access roads to the mine site. The 1,200 acres of the modern titanium mine remain in private hands, one of the few industrially zoned locations in the park. Its mountains of sand, crushed rock, and slag are being sold as aggregate by its new owner, Mitchell Stone Products, which purchased it from National Lead a few years ago.