The mountains lie within the Basin and Range Province or Great Basin of the Western United States , which is characterized by a series of parallel fault blocks that form long north – south mountain ranges separated by wide , high @-@ desert valleys . The Trout Creek Mountains are uplifted and tilted blocks with steep escarpments along the southern and eastern sides of the range . The southern area of the range , known as The Granites , has numerous outcroppings of Cretaceous age granite . These granite outcrops are commonly found in the eroded valleys below the volcanic ridgelines .