The Proposed Rosemont Copper Mine

The Proposed Rosemont Copper Mine

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March 24, 2023
The Proposed Rosemont Copper Mine
A preliminary mine plan of operation (MPO) was submitted
molybdenum, and other mineral by-products. The proposed
to the Forest Service (FS) in 2007 for the proposed
mine would have operated for approximately 25 years.
Rosemont Copper Mine (RCM), located partially within the
Coronado National Forest near Tucson, Arizona (Figure 1).
The MPO proposed disposing of the waste rock and tailings
In May 2022, the U.S. Court of Appeals for the Ninth
on FS and private lands. The proposed mine would have
Circuit affirmed a district court ruling in 2019 that vacated
directly disturbed over 5,600 acres; the waste rock and
the FS’s 2013 Final Environmental Impact Statement
tailings areas would be reclaimed and revegetated, while
(FEIS), 2017 Record of Decision (ROD), and 2019
the 955-acre pit would not be revegetated. Figure 1
approval of the amended MPO. The vacated MPO would
indicates the location and layout of the proposed mine as
have disposed of mine tailings and waste rock on FS lands.
considered by the FS (i.e., the Barrel Alternative).
Given the role copper plays in the U.S. economy and
Figure 1. Location of the Proposed RCM
congressional interest in application of the federal mining
laws, Members of Congress may be interested in the history
of and challenges to proposed mining activities at the RCM.
Copper Background
Copper, recognized for its thermal and electrical
conductivity, is commonly used in heating and cooling
appliances, plumbing, and in electrical applications (e.g.,
wires and cables, windings for transformers, generators, and
motors).
An estimated 26 million metric tons of copper were
produced globally in 2021. The United States in 2021
produced approximately 1.2 million metric tons of copper
in the form of mined ore, and approximately 1.2 million
metric tons from refining operations. Arizona produces
about 70% of domestic copper. In 2021, the United States
was estimated to be the fifth largest producer of copper ore
and the fifth largest producer of refined copper.
The United States consumed approximately 2 million
metric tons of copper in 2021, including over 900,000
metric tons of copper imports.
The Rosemont Copper Mine
The RCM was a proposed open-pit copper mine, consisting
of approximately 995 acres of private land, 75 acres of
state-owned land, and 3,670 acres of mining claims on FS
lands. The mine was originally expected to produce 550
million tons of ore and 1,288 million tons of waste rock

during its 19-year operation. The initial RCM would have
Source: U.S. Forest Service (FS), Final Environmental Impact
processed ore into copper (from oxide ore via solvent
Statement for the Rosemont Copper Project: A Proposed Mining
extraction and electrowinning) and copper concentrate
Operation Coronado National Forest Pima County, Arizona, Volume
(from sulfide ore) at facilities located at the mine.
1, MB-R3-05-6, 2013, p. vi i, at https://cdxapps.epa.gov/cdx-enepa-II/
Additional byproducts would have included silver and
public/action/eis/details?eisId=88299.
molybdenum. Later modifications to the RCM increased the
Notes: The shown “Barrel Alternative” is the option that was
expected ore production and eliminated the planned
selected for further review by the FS.
processing of oxide ores.
Timeline of Recent RCM Events
The RCM was expected to produce approximately 2.7
Copper mining has been occurring in this region of Arizona
million metric tons of copper and 88,000 metric tons of
for over 100 years. The list of dates and actions below
https://crsreports.congress.gov

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The Proposed Rosemont Copper Mine
highlight some of the notable events surrounding the
and Phase 2 is estimated to produce approximately 3.4
proposed RCM.
million tons of copper during the following 28 years. Silver
and molybdenum would also be produced during both
July 2007: Rosemont Copper Company (a subsidiary of the
phases; additional copper could be produced from
Canadian Augusta Resource Corporation) submits a
purchased concentrate. Figure 2 indicates the approximate
preliminary MPO for approval to the FS.
layout of the Copper World Complex described in the PEA.
March 2008: FS publishes in the Federal Register a notice
Figure 2. Proposed Copper World Complex
of intent to prepare an environmental impact statement for
As projected at end of Phase II mine operations
the proposed mine.
August 2010: Hudbay Minerals begins acquiring stock
ownership of Augusta (initially 11% of issued and
outstanding common shares).
October 2011: FS publishes in the Federal Register a notice
of the availability of the draft environmental impact
statement for the mine.
December 2013: FS publishes the final environmental
impact statement (FEIS) and a draft ROD for the RCM.
February 2014: Hudbay Minerals acquires ownership of
Augusta Resource Corporation, including the Rosemont
Copper Company.
July 2015: New Coronado Forest Supervisor appointed.
June 2017: FS issues a final ROD (to satisfy National
Environmental Policy Act requirements) approving the
“Barrel Alternative” for the RCM, after incorporating two
supplemental information reports (SIR), consultations under
the Endangered Species Act (ESA), and an amended final
reinitiated Biological and Conference Opinion from the
U.S. Fish and Wildlife Service (FWS).
March 2019: FS approves amended MPO for the RCM.
July 2019: U.S. District Court for Arizona vacates and
remands the FS’s June 2017 ROD and December 2013

FEIS, halting development of the RCM.
Source: Created by CRS using data from ESRI, the Protected Area
Database of the U.S. (PADUS), and Hudbay Minerals, Inc. (see
October 2019: In response to Hudbay’s petition, U.S.
Hudbay Minerals, Inc., Preliminary Economic Analysis, Copper World
District Court for Arizona finds no basis to reconsider the
Complex, Pima County, Arizona, USA, 2022, p. 16-124).
July 2019 ruling.
Notes: “Hudbay lands” are generalized areas of lands owned or
control ed by Hudbay; some smal areas inside these lands may be
June 2020: Hudbay files an appeal with the U.S. Court of
state or federal lands. “BLM” is the Bureau of Land Management.
Appeals (Ninth Circuit) to reverse the U.S. District Court of
“USFS” is the U.S. Forest Service.
Arizona decision (in July 2019).
Mining on Federal Lands
May 2022: U.S. Court of Appeals (Ninth Circuit) affirms
The General Mining Law of 1872, as amended, (30 U.S.C.
U.S. District Court for Arizona July 2019 ruling.
§§22 et seq.), establishes a mining claim system, where a
Copper World Complex
qualified person has a statutory right to locate a mining
claim on public domain lands for non-leasable or saleable
In July 2022, Hudbay released a Preliminary Economic
minerals. Locating a mining claim requires payment of
Analysis (PEA) for its Copper World Complex, which
certain annual fees; a claim is not valid until a valuable
includes a modified proposal for the RCM. The PEA details
mineral is discovered within the claim. An approved MPO
a two-phase approach: Phase 1 would primarily mine
(or a notice for smaller operations) is required before
resources on private land near the proposed RCM, and
mining operations can begin. Congressional interest in the
Phase 2 would develop the RCM in a similar fashion to
topic includes legislative proposals (e.g., H.R. 1 in the 118th
what was previously proposed; Phase 2 would require FS
Congress) that would allow uses of mining claims other
approval. Phase 1 is estimated to produce approximately 1.5
than for mining.
million tons of copper during the project’s first 16 years,
https://crsreports.congress.gov

The Proposed Rosemont Copper Mine

IF12359
Brandon S. Tracy, Analyst in Energy Policy

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