Questa Mine


The Questa Mine of Chevron Mining Inc. is an underground block cave molybdenum mine and mill

operation located in the Sangre de Cristo Mountains in Taos County. Molybdenum, a silver colored metal found on the periodic table of elements, has the sixth highest melting point of any element, and is therefore commonly used in high-strength steel alloys, catalysts and lubricants. Highly versatile as an alloy, molybdenum improves strength, hardness, toughness, weld-ability, elevated temperature strength and corrosion resistance of other metals.

The Questa Mine is committed — as a company and member of the community — to achieving world-class performance and exceeding the capabilities of its strongest competitors. Molybdenum deposits here are among the highest quality in the world, with several decades of proven reserves. Further development will provide a continuing source of the molybdenum needed worldwide.


The Molybdenum Corporation of America (later Molycorp) began operations at Questa in 1919. The first underground mine at Questa operated into the 1950s, and by that time Molycorp had become the second largest supplier of molybdenum in the U.S. From 1964 to 1983, the mine operated an open pit. In 1983, because of depth of the ore body, the mine once again went underground. Chevron acquired Molycorp and parent company Unocal in August of 2005.

In August 2007, The Pittsburg & Midway Coal Mining Co. officially changed its name to Chevron Mining Inc., merging with Molycorp one month later. Chevron Mining Inc. is a wholly-owned subsidiary of Chevron Corporation.

Mining method

Block cave mining entails undercutting and removing supporting rock from beneath the fractured ore body; skilled miners and engineers cause overlying ore-bearing rock to break under its own weight, gathering into previously excavated areas. It is withdrawn by diesel-powered loaders and transported from the mine via conveyors. Continued drawing of broken ore from below, with drilling and blasting, causes the overlying mass to move downward.


Approximately 400 employees and contractors work at the Questa Mine, which operates 24/7. Throughout its history the mine has employed thousands of residents, providing hundreds of millions of dollars in economic benefits – an approximate value to the state of more than $40 million annually.

The Questa Mine is committed to safe working conditions. Statistics for 2007 demonstrate a safety record significantly better than the industry average. A comprehensive approach includes near-miss reporting, safety observations, and fostering a culture of care and concern for the safety of colleagues in the workplace and at home.


Chevron Mining Inc. advocates environmental stewardship to mitigate the impacts of mining. The Questa Mine works closely with stakeholders and monitors groundwater, surface water and air to ensure operating in an environmentally responsible manner: 

Best Management Practices (BMPs) include water management and waste minimization; Innovative reclamation practices have been developed to ensure that areas disturbed by mining are reclaimed in a manner consistent with the surroundings.


The Questa Mine actively participates in the community, including employee volunteerism, equipment donations and monetary contributions. The Community Grants Program, administered quarterly by the mine’s Employee Contribution Committee, provides funding, in-kind donations and volunteer support for organizations throughout northern New Mexico.

The Questa Mine’s Sustainability programs create long-term value for the community

in focus areas including youth and education, health and human services and economic development. Educational initiatives include ongoing professional and vocational development programs for employees, community scholarships for higher education, work-study positions for high school students, and internships for college students.


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