The west central part of the Malad Range is located in south-eastern Idaho. This area was the site of thick marine deposition in the early Paleozoic period. In the Tertiary and Quaternary periods continental deposition occurred, covering the Paleozoic rocks. Quartzite and shale units of the Brigham Quartzite are found near the base of the Cambrian section. Carbonate with shale interbeds is found in the middle and late Cambrian units. Limestone and silty limestone are found in the early and middle Ordovician time overlain by the middle Ordovician Swan Peak Quartzite. The Laketown Dolomite includes units of late Ordovician and Silurian age. Paleozoic units younger than Silurian and and Mesozoic units are not found in the mapped area. Red conglomerates mark early Tertiary deposition, and water-lain tuff, fresh-water limestone, conglomerate and sandstone are of middle and late Tertiary age. Tertiary-Quaternary rocks, found in the mapped area, are composed of deposits of boulders resting on older Tertiary and Paleozoic rocks. These deposits show rough polygonal structures and stone stripes. Quaternary deposits are composed of sediment from the Late Pleistocene Lake Bonneville and Quaternary alluvium. Northwest-trending faults, northeast-trending faults, and north-trending faults are found in the mapped area, with northwest-trending faults predominating. The northwest-trending faults are high-angle faults and have resulted in Tertiary rocks being faulted against lower Paleozoic rocks. Northeast-trending faults are roughly parallel and predate the middle and late Tertiary rocks. North-trending faults are high-angle faults involving both Paleozoic and Tertiary rocks. One northwest-trending fault has evidence of horizontal movement. The structures are assigned to three periods of movement: 1. early Cretaceous to early Tertiary, 2. late Tertiary to middle Tertiary, 3. middle Tertiary to Recent.

The central part of Clarkston Mountain is located in northcentral Utah in the southern part of the Malad Range. It is northwest of Clarkston, Utah. The mapped area measures 2.5 mi. in the north-south direction and 6.5 mi. in the east-west direction. It is within the Basin and Range Province. The Ute Formation of Middle Cambrian age is the oldest exposed stratigraphic unit. Other Cambrian units, in ascending order, are: Blacksmith Formation, Bloomington Formation, Nounan Formation, and St. Charles Formation. These units consist predominantly of limestone, dolostone, and shale. Units of Ordovician age include the Garden City Formation and the Swan Peak Formation. They consist of limestone and orthoquartzite, respectively. The youngest Paleozoic unit is the Fish Haven-Laketown Formation of Ordovician-Silurian age. It is dolostone. Units of Quaternary age include colluvial deposits, Lake Bonneville Group, and alluvial deposits. West-dipping, low-angle normal faults generally trend north and northwest. They were originally thrust faults formed during regional compression. A bedding-plane thrust fault separates the Bloomington and Nounan Formations. Later reversed movement on the west-dipping, low-angle thrust faults changed the stratigraphic relationships across these faults to those characteristic of normal faults. High-angle normal faults trend northwest, north, and northeast. Major normal faults extend along the western and eastern sides of Clarkston Mountain and are responsible for the present topographic relief. The structural features of the mapped area are the result of two major tectonic events. The Sevier orogeny produced eastward directed thrust faults. It began in Late Jurassic and ended in early Eocene. Basin and Range normal faulting caused reversed movement on west-dipping thrust faults, formed by the Sevier orogeny, and also produced many high-angle normal faults. It began in early Eocene and has continued into historic time in the region.

Rocks of Paleozoic, Tertiary, and Quaternary age are represented in the northern part of the Malad Range. The Paleozoic rocks are represented by thirteen formations that are characterized lithologically by quartzites, shales, and carbonates. The oldest formation in the mapped area of Paleozoic age is the Brigham Formation, and the youngest formation is the Jefferson Formation of late Devonian age. The rocks of Tertiary age are conglomerates, shales, and limestones and are represented by the Wasatch Formation, the Salt Lake Formation, and boulders. Quaternary rocks include sediments of the Lake Bonneville Group and alluvium. The faults in the mapped area were formed during two periods of movement. The east-west-trending faults, northeast-trending faults, and northwest-trending faults are a consequence of compressional forces during Laramide orogenic activity. The north-south-trending faults were the result of Basin and Range block faulting during middle and late Tertiary times.