Southern Arizona's Historic Mining District

History of the Rosemont Mining District

Copper became the focus of mining in the Santa Cruz Valley and elsewhere in southern Arizona beginning in the late 1880s. The advent of the electrical age and World War I continued to increase the demand for copper during the next three decades. While some copper mines and associated settlements developed in the Santa Cruz Valley, the most important mines and all smelters were opened in neighboring valleys between 1885 and 1918. By 1900, copper production in southern Arizona had risen to three times the value of Arizona’s combined gold and silver production, and the region led world copper production by 1907.

Helvetia Store

In the Santa Cruz Valley, Helvetia was one of the richest copper mines during the 1880s and 1890s, operated primarily by the Helvetia Mining Company. Copper mining began in the Sierrita Mountains in the Twin Buttes region about 1870, and by 1903, the Twin Buttes Mining and Smelting Company was operating several shaft mines, and a major mining camp had sprung to life. Establishment of a post office and completion of the Twin Buttes Railroad branch connected the boomtown of Twin Buttes — with some 300 residents — to the Southern Pacific Tucson-Nogales line at Sahuarita in 1906.

Rosemont Mining District

The Rosemont Mining District is believed to have been worked before the Civil War, but it was not until the 1870s that the first mining claims in the area were staked. The Narragansett claim, struck by J.K. Brown in 1879 was the first, followed by the Eclipse claim by M.L. Geroud in 1884 and Backbone claim by Thomas Deering and William McCleary in1885. McCleary, backed by investors and his friend J.L. Rose, established the Rosemont Smelting and Mining Company. By 1894, the company consisted of 30 developed claims and a camp, which grew to become the first location of the community of Old Rosemont. The same year, 50 men were hired to begin development of a smelter site and mine. Within four months, the first smelter had been erected.

Unfortunately, less than a year later, financial troubles for McCleary and Rose forced them to sell the mine and camp to the Lewisohn brothers of New York. The brothers paid between $30,000 and $40,000 for 46 claims and seven mill sites, which were surveyed and patented by 1899. Approximately 75 men were hired to work at the Rosemont mines prior to the claims being patented, resulting in a 1900 U.S. Census listing 234 residents in or near Rosemont.

During the early years at Rosemont, the town included typical mining facilities, including a smelter and assay office, as well as a schoolhouse, hotel, blacksmith shop, post office and general store. A stage line was also established sometime prior to 1899, connecting Old Rosemont to the Pantano and Vail stops via the Southern Pacific Railroad. Incoming and outgoing goods were shipped regularly using the New Mexico and Arizona Railroad, which also made stops in Sonoita and Tucson.

In 1899 through 1903 regular fuel shortages halted production and the smelter was left to idle before being permanently shut down in 1907.

In 1915, the Narragansett Mines Company restarted production at the original claim site employing over 250 miners. During the height of its occupation in 1920, New Rosemont was home to 350 miners, families, ranchers and business owners. By 1926 the majority of work had come to a halt at Rosemont but various mining groups worked the Narragansett and neighboring claims with some success from 1938 to 1973.

Helvetia Mining District

Named by miner Ben Hefti in honor of his native Switzerland, Helvetia became a boomtown in 1875, when two entrepreneurs discovered vast reserves of copper ore in the northern end of the Santa Rita Mountains.

Omega Copper Co. and Columbia Mining and Smelting Co.were the first major developers of the Helvetia Mining District. The first mine, Old Frijoli, was located in 1880 by Bill Hart and John Weigle. Other mines included Old Dick, Heavyweight and Tally-Ho discovered by L. M Grover. The first smelter was completed in 1882 and by 1883 twenty claims had been recorded in what became known as Helvetia Copper Group.


Unfortunately, that same year, the depression of copper prices and poor management caused the mining operations to cease production. It would be nearly a decade before a second boom would begin, thanks in part to Thomas Edison’s newest invention – the light bulb. Demand for copper wiring soared, sending miners back to work and new developers to the area.

By 1899, the Helvetia Copper Company of New Jersey was operating the largest mining camp in Pima County, employing nearly 500 men. Within a dozen years, several permanent company buildings, a line of tents, adobes and grass shanties to house workers, 4 saloons, a hotel, post office, school, Chinese laundry, shoe maker and butcher shop had sprung up from the dirt. Two Tucson stage lines regularly carried passengers to and from Helvetia.

Rosemont Meltor

Workers, organized by the Western federation of Miners, were paid $1.25 to $1.50 a day for surface work and $3.00 a day to work underground. It was the merchants, however, who made money, grossing $10,000 a month at the peak of mining activity. Helvetia became the third largest school district in Pima County, with nearly 100 students enrolled in the tiny school house during one year. Disaster befell the Helvetia Mining District in 1900. In December, with the smelter running at full capacity, a large mass of slag ran onto the wooden floor of the building, igniting timbers and burning it to the ground. The fire served a crushing blow to the Helvetia Copper Company, and although the smelter was rebuilt in 1902, the company never recovered.

The Michigan and Arizona Development Company acquired controlling interest in the Helvetia Copper Company a year later and built yet another smelter. Work was concentrated on the most profitable claim, keeping the business alive until 1911, when the low price of copper forced the mine to close and its machinery to be sold.

Sporadic mining activity continued throughout the 1920’s, with small, intermittent shipments of ore by lessees. In late 1923, with fewer than 10 students left in the local school, it was shut down for good and the city fathers moved away.

Copper production hit a small peak between 1944 and 1947, and it’s estimated that by 1950 the Helvetia Mining District had produced 17,000,000 pounds of copper worth approximately $4,000,000.

There was little activity at the site in the 1950’s and by 1960 Helvetia was occupied by transients living in the abandoned buildings, including the Rosemont Hotel. The old structures were bulldozed a short time later.

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