Beyond the cache location Hanson Quarry (aka Kaiser Quarry) mined sand from the 10 million year old Santa Margarita Sandstone formation for 44 years until 2003 at which point quarrying stopped and all former mineral processing facilities were removed and disturbed areas treated with a long term reclamation plan which includes grading, re-vegetation including large-scale plantings on the quarry floor, drainage and erosion control, creation of a retention pond and conversion of the existing settling ponds into a series of detention ponds.
Every 5 years the permit is subject to review by the Planning Commission for compliance with operating conditions and for possible amendment for mitigation of environmental and community impacts. The revegetation’s progress will be reviewed every five years until 2030.
The mine is located within the sensitive Sandhills habitat west of the City of Scotts Valley. The Sandhills include many sensitive and endangered endemic species including the Mount Hermon June beetle, Zayante band-winged grasshopper, Santa Cruz kangaroo rat, Santa Cruz wallflower, and the Ben Lomond spineflower as well as at least eight other species. Hopefully someday this land will be added to the Randall Morgan Sandhills Preserve that sits to the NW of the Hanson acreage.