Mining vehicles harvest Franciscan melange, a stone found at the base of Bishop Peak, from a quarry off Foothill Boulevard on Thursday, Aug. 15, 2024.

A Madonna Ranch quarry at the foot of Bishop Peak in San Luis Obispo, California, supplies material for a repair project at Big Sur Lookout on Highway 1.

Mining vehicles harvest Franciscan melange, a stone found at the base of Bishop’s Peak, from a quarry on Foothill Boulevard Thursday, Aug. 15, 2024.