Hudbay’s US properties are the Rosemont project, located in Arizona, and the Mason project, located in Nevada.

The Mason deposit, acquired in late 2018, is one of the largest undeveloped copper resources in the Americas. It is similar in scale to Constancia and Rosemont.

In production, the Rosemont project will be one of the largest copper mines in the United States, with an expected mine life of 19 years.

The copper at Rosemont will support a cleaner, interconnected economy by supplying critical materials in accordance with some of the world’s most stringent labour and environmental standards.

In July 2019, the US District Court for Arizona issued a ruling that vacated the Final Record of Decision (FROD) issued by the US Forest Service. As a result, our ability to move ahead with building Rosemont is suspended for the time being. Simply put, the judge ruled that the decision to issue the FROD was based on an incorrect interpretation of mining claims.

We have appealed the ruling. Hudbay believes that the Court misinterpreted federal mining laws and Forest Service regulations as they apply to Rosemont.

The metal from Rosemont will be a vital part of technology in daily life, the green economy and Arizona’s future.

Utilizing leading-edge mining technologies, Rosemont will help define safe and sustainable 21st-century mining practices that will support America’s clean energy economy. Rosemont is striving to raise the bar for what it means to safely and sustainably mine copper and other essential minerals – to minimize impacts to the landscape and water and to enrich partner communities in ways that outlast the course of mining operations.

Number of Employees Expected During Operation


Expected Mine Life

Rosemont: 19-year mine life


Rosemont will use the dry-stack method of tailings storage. Dry stack eliminates storage ponds, uses 50% to 60% less water than similarly sized mines, and extracts about 85% of the water that is used, for use again.

Key Production Metrics

$1.921 billion capital cost
15.5% after-tax unlevered IRR at $3.00/pound copper
127,000 tonnes of annual copper production in first 10 years
Cash cost of $1.14/pound net of by-product credits, in first 10 years


In production, water consumption at the Rosemont mine will be among the lowest in the world per pound of copper produced. Rosemont will replace all the water used at the operation and has already purchased and stored approximately 45,000 acre-feet of water, equivalent to the amount Rosemont will use in its first eight years. This water will be returned to the Rosemont-area aquifer through recharge of the Central Arizona Project (CAP), a water replenishment program. Additionally, as part of the project, we expect to contribute $28 million toward building an eight-mile pipeline and water recharge facility that will bring CAP water to the region.

Of water used for the operation of Rosemont will be replaced


We are part of the communities in which we operate. The permitting and public comment period for Rosemont provided us with a greater understanding of nearby communities’ priorities, and these are reflected in Rosemont’s numerous commitments to contribute to the region’s long-term economic prosperity and well-being. Once the mine is in operation, a $25 million trust will be dedicated to conservation, recreation, cultural and environmental projects and education. Additionally, an annual contribution of $500,000 for 25 years (a total of $12.5 million) will be made to support community giving. A total of $12.5 million will be prioritized to support education, social services, job training, and organizations that support military personnel and veterans.

$25 million
For conservation, recreation, cultural and environmental projects and education
$12.5 million
For community giving over 25 years


Navigable Waters of the U.S.


After a construction decision is approved, Rosemont will prioritize hiring from within local communities and will require up to 2,500 workers during the peak construction period. We continue to engage with local businesses, organizations and universities to identify resources, local talent pools and opportunities to build a pipeline of potential future employees. In production, Rosemont is expected to directly create over 500 full-time jobs. Annual wages for direct employees are expected to average more than twice the current median annual income in Pima County.

Jobs expected during the peak of construction at Rosemont
Full-time jobs once production begins and for the duration of the estimated 19-year mine life

Reserves and resources - Rosemont

Rosemont Project Mineral Reserve and Resource Estimates1

Category Tonnes Cu Grade(%) Mo Grade(%) Ag Grade(g/t)
Mineral Reserves2,3
Proven 426,100,000 0.48 0.012 4.96
Probable 111,000,000 0.31 0.010 3.09
Total proven and probable 537,100,000 0.45 0.012 4.58
Mineral Resources 3
Measured 161,300,000 0.38 0.009 2.72
Indicated 374,900,000 0.25 0.011 2.60
Total measured and indicated 536,200,000 0.29 0.011 2.64
Inferred 62,300,000 0.30 0.010 1.58

Note: totals may not add up correctly due to rounding.

1 Based on 100% ownership of the Rosemont project.

2 Blocks were classified as Proven or Probable in accordance with CIM Definition Standards 2014.

3 Mineral reserves and resources calculated using metal prices of $3.15 per pound copper, $11.00 per pound molybdenum and $18.00 per ounce silver.

Reserves and resources - Mason

Mason Project Mineral Reserve and Resource Estimates

Category Tonnes Cu (%) Au (g/t) Ag (g/t) Mo (%)
Measured & Indicated 1,400,000,000 0.32 0.03 0.65 0.006
Inferred 623,000,000 0.29 0.03 0.66 0.007