While Sedona is famous for its red rocks, the landscape surrounding Camp Verde is known for its stark white rock. Those rocks form what geologist call the Verde Formation, a layer of sediments roughly 40 miles long, 20 miles wide and nearly 2,000 feet thick, laid down by a shallow lake that once spread across the valley floor.
Geologist estimate the lake, dubbed Lake Verde, was a feature on the landscape 10 million to about 2 million years ago. It is believed the lake formed atop the graben, a keystone shaped slab of crust, that forms the valley floor and descended to its current elevation as the graben subsided and began forming the valley. The evaporite minerals that make up the Verde Salt Mine as well as a gypsum mine in Camp Verde formed when the lake dried up and left behind white minerals.