Hudbay says it is developing plans to build at least three open-pit copper mines on west side of Santa Rita Mountains

Click to enlarge.

Four years after stating there were substantial copper resources adjacent to the proposed Rosemont Mine on the northeast flank of the Santa Rita Mountains, Toronto-based Hudbay Minerals, Inc. is now saying it plans to develop at least three open-pit mines on the ridgeline and down the west side of the range overlooking Sahuarita and Green Valley.

The company has outlined a sprawling mining development that would destroy a section of the Santa Rita’s ridgeline and possibly connect the west side mining operations called Copper World with the proposed Rosemont Mine on the northeast flank of the mountain.

Hudbay’s preliminary plans are outlined in a mine reclamation plan submitted to the state and in a recent press release and investors’ report. Hudbay has not completed a formal economic analysis of the project nor a feasibility study required under Canadian mining laws before mining can begin. Hudbay states it expects to complete the reports next year, followed by two years of permitting, three years of construction with mining starting in 2027.

The Copper World mining project and adjacent exploration, so far, is all on 4,500 acres of private land acquired decades ago through provisions in the General Mining Act of 1872 and recent purchases. Hudbay would only need three state permits for the Copper World project unless it expands mining operations onto adjacent U.S. Bureau of Land Management property, according to an Oct. 3 report in the Arizona Daily Star.

Hudbay told the newspaper it has 101 unpatented mining claims on the BLM land, which would allow the company to explore and develop mine operations while the BLM retains ownership of the land. However, the BLM would have to approve any development on its land. Mining on the BLM line would also require obtaining federal permits that have delayed the development of the Rosemont mine.

On the east side of the mountain range, Rosemont has a mix of primarily private land where the mile-wide, half-mile deep pit is planned and more than 2,000 acres of Coronado National Forest where Hudbay plans to dump waste rock and mine tailings.

Rosemont construction was stopped in July 2019 by a Tucson federal court ruling which Hudbay and the U.S. Forest Service subsequently appealed. A hearing was held last February, and a ruling from the 9th Circuit Court of Appeals is expected later this year. However, there are additional pending lawsuits against Rosemont that are unresolved.

While Hudbay is telling investors the west side deposits are “new discoveries,” Hudbay and the previous owner, Augusta Resource Corp., have long known about the potential to develop the deposits that are near the surface and extend to a much shallower depth than Rosemont.

In a 2017 Rosemont feasibility report, Hudbay identified “economic” copper deposits of nearly the same size as Rosemont in areas adjacent to the Rosemont pit, including some of the same area where Copper World is now touted as a new discovery.

(Click on graphic to enlarge.) The dotted line encompasses the resource pit shell. The actual Rosemont pit would be constructed within the the resource pit shell.

In February 2014, Augusta Resource Corporation filed documents with Canadian securities regulators providing details of the expansion and exploration potential for areas adjacent to the Rosemont site.

Augusta stated that an additional 3 billion pounds of copper may exist near the Rosemont site and, if developed, “could significantly increase annual production and mine life.”

In 2012, Augusta stated in a technical report that “mineralization” at the Broadtop Butte mining claim located about a mile north of the proposed Rosemont pit along the ridgeline  of the Santa Rita Mountains “could potentially be added as a satellite development.” Broadtop Butte is now included in Hudbay’s Copper World plans.