Located in Lake County beside Fremont Pass, the Climax Molybdenum Mine started production in 1918 and grew to become the world’s largest underground mine. Deemed a national priority during World War II because of molybdenum’s importance in hardening steel, Climax continued to grow for a generation after the war. A molybdenum price crash sent the mine into a tailspin in the 1980s, devastating the local economy. After decades of maintenance and environmental restoration, the mine resumed production in 2012.
The first people to come to Fremont Pass in search of precious metals probably arrived around 1860, as prospectors attracted by the Colorado Gold Rush fanned out across the central Rocky Mountains dreaming of new discoveries. Near the pass itself, they saw only a metallic, dark gray deposit that they assumed was graphite or galena. In the late 1870s, the Leadville silver boom drew another wave of prospectors to the area. Charles Senter ventured north to Fremont Pass and became the first person to stake a claim to the gray rock on nearby Bartlett Mountain, though he did not bother to file his claim for more than a decade. In the meantime, the Denver & Rio Grande Railroad completed a line to Leadville in 1880 and then continued north over Fremont Pass, naming the spot at the top of the pass Climax.
In 1895 a Colorado School of Mines professor determined that the gray rock at Bartlett Mountain was molybdenite, a mineral made of molybdenum and sulfur. This discovery did not spark any serious interest in the area, however, because there was little demand for molybdenum-hardened steel and the ore at Bartlett Mountain was low-grade, requiring a lot of work for a little molybdenum.
Real mining at Bartlett Mountain started in the 1910s. Molybdenum demand increased sharply that decade, first as European countries geared up for war and then as World War I demonstrated the clear superiority of molybdenum-strengthened steel. The major local breakthrough came in 1915, when Otis King developed a process for separating molybdenum from molybdenite. Within two years, three separate companies employing several hundred workers were competing to develop claims near Climax.
The most important of the companies at Climax was a syndicate organized by Max Schott of the American Metal Company. Incorporating as the Climax Molybdenum Company in early 1918, it opened a mine and mill that February and was able to ship its first molybdenum by April. In its first year, the Climax Mine was already the largest mine in Colorado. It took over most of the claims of its two competitors, who sold out in late 1918 as World War I ended and as the molybdenum market dipped. The Climax Mine also had to stop production within a year because European steelmakers no longer needed molybdenum and were dumping their reserves.
Building a Company
In 1919 Brainerd Phillipson took over Climax Molybdenum, putting him at the head of a business that had a warehouse of molybdenum but nobody to buy it. Phillipson promoted molybdenum as an American metal and offered free samples to any company that wanted to experiment with potential uses. These efforts gradually increased demand, particularly among automobile makers. By August 1924, it finally made sense to resume production. Soon Climax Molybdenum was processing an average of 475 tons of ore per day, good for 75 percent of world production.
Phillipson died of diffused meningitis in October 1930, at the age of forty, just as the Great Depression began to destroy domestic molybdenum demand. Max Schott, who had organized the original Climax syndicate, took over the company the next year. Under his leadership, Climax continued producing continuously through the 1930s thanks to strong molybdenum export markets. The company controlled 86 percent of world production by 1935.
Despite strong production, Climax had persistent problems with its workforce. Underground mining at 11,000 feet was cold, dangerous work. Turnover rates were high, with miners calling Climax “the hellhole on the hill.” After a major blizzard in 1936 isolated Climax for weeks, the company pushed to develop attractive worker housing at the mine. The company saw war looming and anticipated that it would need an expanded workforce to deal with increased demand. That summer, boardinghouses gave way to single-family houses, apartments, a recreation center, a hospital, and a school; a ski area opened the next winter. The $4 million construction project quickly yielded results, as Climax employment doubled from 600 in 1936 to more than 1,200 in 1937.
War and Prosperity
As the company anticipated, demand for molybdenum shot up at the end of the 1930s as the world prepared for war. But the government quickly stepped in to regulate production and sale of the important wartime material. When fighting began in Europe in 1939, President Franklin Roosevelt asked Climax to suspend sales to potential adversaries. After the United States entered the war at the end of 1941, the War Production Board gave Climax the highest operating priority of any mine in the country, demanded sharp increases in production, and posted a unit of the US Army Auxiliary Military Police to guard the mine. By June 1943, production was more than twice what it had been before the war; over the full course of the war, the company shipped a total of 180 million pounds of molybdenum.
Then, with the end of the war, the feverish production suddenly stopped. By fall 1945, Climax slashed production by three-quarters and employment by two-thirds. Nevertheless, the company nimbly navigated the postwar period, embedding itself within the new military-industrial complex. The War Production Board’s chief of staff, Arthur Bunker, became company president in 1949, and he successfully advocated for a federal stockpile of molybdenum as a Cold War safeguard. Along with the stockpile, the start of the Korean War in 1950 boosted demand, allowing the company to invest in increasing production capacity and improving its company town. By 1953 workers at Climax had an expanded hospital and school, a lighted baseball field, a full shopping center with a grocery store, and the first commercial television service in central Colorado.
The 1950s were a golden age for Climax Molybdenum. Even with the end of the Korean War, the company managed to keep production high by marketing molybdenum for industrial uses. Production outpaced even World War II levels, and employment remained steadily above 1,000. The company town had more than 1,500 residents, who benefited from full employment and low rents. By 1958 Climax had become the largest underground mine in the world. With other mines around Leadville long in decline, the company accounted for half of Lake County’s workforce as well as three-quarters of the county’s property taxes.
At the end of the 1950s, Climax experienced two major changes that transformed the relationship between the company, its employees, and the community. First, on January 1, 1958, Climax Molybdenum merged with the American Metal Company, making it a division of American Metal Climax. Around the same time, Climax decided to shut down its company town. Not only was employment expanding beyond what could be housed there, but also better roads and cars were making it easier for employees to commute the twelve miles from Leadville. The company developed a new subdivision near Leadville, then in 1959 decided to move the entire company town down the hill as well to make way for future mining. Completed by September 1962, the move bound Leadville tightly to Climax.
Distant corporate ownership and new distance between workers and management led to more contentious workplace relationships. When an economic downturn in 1958 caused a production cut, a shortened work week, and frozen wages, the Climax Molybdenum Workers Union voted to go on the first strike in the mine’s history. After three months, the union agreed to a small wage increase and went back to work. A second strike—over wages, work rules, and arbitration—started in July 1962. This strike lasted longer than the first and demonstrated the extent of Leadville’s dependence on the mine (four local businesses closed during the strike) and the power the mining company had over its employees. When the strike dragged on into the fall, Climax unilaterally resumed production to prevent the mine from freezing. In January the union settled for a small increase in pay and improvement in benefits.
Despite labor difficulties, Climax continued to dominate the world molybdenum market—accounting for 61 percent of world supply in 1963—and to expand its operations. In May 1964, the company detonated the largest underground explosion in mining history in order to break 1.5 million tons of ore from the side of Bartlett Mountain. The explosion, which used 208 tons of powder, generated energy equivalent to a tactical nuclear weapon. In the early 1970s, the company added to its underground production by starting open-pit surface mining to counter increasing competition from foreign mines. Climax set annual production records throughout this period, reaching 61 million pounds of molybdenum in 1976.
Record-high molybdenum prices kept Climax profitable through the 1970s, even as new environmental regulations and rising payroll expenses for its 3,000 employees made the cost of production climb. But high prices also resulted in a worldwide molybdenum glut, which suddenly became clear as a recession hit in 1980. In 1981 the mine started to cut production and lay off workers. After suspending production for a month in July 1982, the mine stopped production indefinitely that September. In 1983 parent company AMAX reopened the nearby Henderson Molybdenum Mine as prices recovered, but the company kept Climax closed because of its high production costs. In 1987 AMAX ordered a full shutdown at Climax
The decline of the Climax Mine destroyed the Lake County economy, which depended on steady wages and property taxes rolling down the hill. From 1980 to 1982, the county lost nearly one-third of its population, while school enrollments fell by half. Housing prices declined, and stores closed. By 1983 things were so bad that Ken Chlouber, a Climax employee and Lake County commissioner, helped stage a 100-mile running race in Leadville to draw visitors. Many people accepted lower pay and longer commutes to do seasonal work at resorts in Summit and Eagle Counties. By the end of the 1980s, Lake County had lost half its population, leading the nation in demographic decline.
Climax resumed limited mining operations in 1989, but the mine’s few full-time employees focused largely on maintenance and environmental restoration. In the roughly seventy-five years since it had opened, the mine had taken 940 billion pounds of ore from the earth, yielding 1.9 billion pounds of molybdenum. This produced great profits but also had high costs: Bartlett Mountain had been destroyed, and Ten Mile Canyon was converted into a series of tailings ponds. Climax’s efforts to correct the damage kept the mine from becoming a Superfund site; in the 1990s, its ongoing investments in water treatment allowed it to sell water rights to ski resorts in Summit and Eagle Counties.
By this time, production at the once-dominant Climax Mine depended on corporate managers and market prices. After a spurt of production in 1995, the mine closed for the next seventeen years as new owner Phelps Dodge focused on the Henderson Mine. Finally, in 2012, after Freeport-McMoRan acquired the mine and invested roughly $750 million, Climax resumed production with about 400 employees.
Today Climax continues to produce molybdenum, with a full operating capacity of about 30 million pounds per year. Roughly half of its employees live in Lake County, but Leadville is less dependent on the mine than it used to be. Its economy diversified between the 1980s and the 2010s, becoming more tourist-oriented thanks in part to the success of the Leadville Trail 100 race. The community learned the hard way that it must plan ahead for the next time Climax closes, which will probably be for good. Given current production levels and known reserves, the mine is expected to last until the late 2030s.