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.

The quarry sits on Madonna Ranch land on the northern side of Foothill Boulevard just west of the city limits. It’s visible on the flanks of Bishop Peak, where piles of gray rock have been ...

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.