The Monte Cristo Range is part of the extensive Basin and Range physiographic province of North America. Like most of the mountain chains in the Basin and Range Province, the Monte Cristo Range is an uplifted block of igneous and sedimentary rocks bounded by deep, alluvium-filled valleys. But the Monte Cristos differ from the majority of mountain chains in the province in one important aspect. The Monte Cristo Range is an arcuate, crescent-shaped chain of mountains while most of the other chains are linear and trend north-south. More than one writer has noticed the distinct, caldera-like shape of the Monte Cristo Range. Could the Monte Cristos be the remnant of an ancient caldera complex?
The Monte Cristo Mountains are an uplifted volcanic complex consisting of various Tertiary extrusive rocks with some small isolated exposures of lower Paleozoic siliceous clastic sedimentary rocks and volcanics. The Tertiary volcanics consist of upper-Tertiary basalts, andesites, and rhyolites, slightly older tuffaceous sediments, and older still silicic tuffs and rhyolites of mid-Tertiary age.
The rugged peaks that form the crest of the range are composed of the Gilbert Andesite, a series of lava flows and volcanic breccias. The Gilbert Andesite makes up most of the southeastern quarter of the range. The northern portion of the range is dominated by a thick blanket of Tertiary basalts. These mafic volcanics consist of a series of basalt flows interbedded with sandstone and conglomerate. Most of the remaining portions of the range consist of silicic ash-flow tuffs and rhyolites with occasional exposures of lower Paleozoic siliceous clastic sedimentary rocks. The largest of these exposures of ancient Paleozoic basement rock occurs in the southwestern portion of the range.
The northern part of the Monte Cristo Range is apparently cut by a major fault zone that trends roughly east-west. In addition, at least two small sections of the range are marked by broken, highly faulted rocks. These include the southwestern edge of the Monte Cristos and the northeastern section, near Crow Springs.
The Monte Cristo Range is literally surrounded by rich mining districts. From the crest of the range, near Doyle Peak, one can gaze southeastward across the Big Smoky Valley and see one of the greatest mining districts in North America. There, only 25 miles away, lies the famous silver and gold district, Tonopah. The Silver Peak District is located 35 miles straight south of the Monte Cristos, while the Candelaria silver lodes lie only 20 miles west of the range. Northwest of the Monte Cristos, the Pilot Mountains gradually rise up from the surrounding hills. Only 20 miles away, the Pilot Mountains are home to a number of small gold mines and several rich turquoise deposits. Likewise, the Royston Hills District is also a source of excellent turquoise. Lying only 16 miles north of the Monte Cristo Range, the Royston Hills have been worked for centuries for their turquoise deposits. In 1921, a rich deposit of silver was discovered in the Royston Hills but the vein quickly petered out. Royston has slumbered since.