The Franklin Mountains extend from just north of downtown El Paso in El Paso County into southern Doña Ana County, New Mexico; their center is at 32°01' north latitude, 106°32' west longitude. They are roughly three miles wide by twenty-three miles long and rise to an elevation of 7,192 feet above sea level at North Franklin Mountain. The mountains divide the city of El Paso and have influenced its shape and growth. This range comprises the bulk of the second largest state park in Texas and what is said to be the largest urban park in the nation, Franklin Mountains State Park.
The Franklin Mountains are composed primarily of sedimentary rock with some igneous intrusions. Geologists refer to them as tilted-block fault mountains, and in them can be found billion-year-old Precambrian rocks, the oldest in Texas. The Franklins were formed during the Laramide mountain-building period in late Cretaceous time, 60 million to 70 million years ago. Typical Chihuahuan Desert plants and animals are found in the Franklins and some, such as the large barrel cactus, are found nowhere else in Texas. El Pasoans are especially fond of the native Mexican poppies and introduced California poppies that tint the rocky slopes each spring. Animals range from many species of rodents to deer, mountain lions, and occasionally black bears. Though the mountains look arid, a number of springs can be found during periods of adequate moisture. These springs are particularly conducive to plant and animal life. Stands of cottonwood, hackberry, oak, and juniper grow in some of the more remote areas of the park.
The name Franklin may have been derived from that of Franklin, Texas, in El Paso County, which in turn was named for Benjamin Franklin Coons (see EL PASO, TEXAS). Other sources suggest that the profile of Benjamin Franklin can be seen in some of the rocky crests. Early Spanish maps referred to the range as Las Sierras de los Mansos (an Indian tribe the Spanish found along the river at El Paso) or Las Sierras de los Organos (for the organ-pipe shapes of some of the cliffs). Early Spanish and Mexican settlers usually avoided the mountains because Apache and Comanche raiders used them as bases for their raids upon the river settlements.
Outlaws also used the rugged isolation of the Franklins. At Fussellman Canyon, in an encounter with rustlers in 1890, deputy United States marshall Charles H. Fussellman was killed in a shootout. The outlaw Gerónimo Parra was later hanged for the shooting.
Small quantities of tin were produced in the Franklin mountains in the early 1900s. A mine founded in 1909 and operated by the El Paso Tin Mining and Smelting Company, proved unsuccessful; work was stopped in 1915 after the project yielded only 160 100-pound pigs of tin (see TIN SMELTING). The legendary Lost Padre Mine is said to be hidden somewhere in the mountains. The tale says that some 300 burro loads of silver were left by Jesuits, who filled in the shaft before fleeing the area. Other versions state that 5,000 silver bars, 4,336 gold ingots, nine burro loads of jewels, and four priceless Aztec codices were hidden in the shaft by Juan de Oñate. Local newspapers periodically report someone's claiming to have found the fabled treasure, only to lose it again or run out of capital before it can be recovered.