The Domenigoni Mountains are composed primarily of metamorphic rock of the Triassic - Jurassic French Valley formation within Searls Ridge and the 1967 foot summit across the saddle to the west of it.

The extreme eastern end of Searls Ridge and the western extreme of the 1967 foot summit of the range are Cretaceous granitic rock.

The range and valley are named for Italian-American landowner Angelo Domenigoni, who purchased the land in 1879.

Searls Ridge and the 1967 foot summit of the Domenigoni Mountains across a saddle to the west of it, enclose Diamond Valley Lake on its northern shore together with the Rawson Mountains on its southern shore.

The dams were built within the rock of the French Valley formation in both ranges.