Geologically, the Trinity Alps consist of a mixture of igneous, granite and metamorphic peaks. In the eastern mountains are the Red Trinities, due to reddish ultramafic peridotite, in the central granitic batholith are the White Trinities, and in the western mountains are the Green Trinities due to more extensive forest cover. The region contains much pine and fir forest as well as meadows, creeks, and lakes.
