This staircase is contructed in solid slabs of gray and tan limestone on a compacted gravel base in Mill Valley, California. The weight of the stone makes this extremely stable even without any concrete structure. This entire project included stone bridges, columns, fireplaces and an outdoor BBQ. There was also a tighly cut stone patio as well.
The suppliers were American Soil Products in San Rafael, California, Peninsula Building products in Sunnyvale and Redwood City, and W. Johnson Ornamental Stone in Santa Rosa CA