ROSEMONT RANCH

Augusta Resource reported to have received written notification from the Arizona State Mine Inspector that the Rosemont Copper Project Mined Land Reclamation Plan has been approved. The Rosemont reclamation plan calls for reclamation to begin after the first year of production and continue concurrently throughout the life of the project. Rosemont has contracted with the University of Arizona to study which native plants will re-vegetate most quickly to support the habitat, and to date that work has been limited to greenhouse research. With the approval by the Mine Inspector of the reclamation plan, these studies can now include construction of test plots on the site to evaluate the greenhouse re-vegetation results into the real setting in which they will be utilized.

Augusta Resource Corporation has updated the August 2007 Bankable Feasibility Study on its 100%-owned Rosemont Copper Project in Pima County, Arizona. The Updated Feasibility Study (“UFS”) re-confirms Rosemont as an economically robust open pit copper/molybdenum mine with low development risk. Using long-term metal pricing of $1.85 per pound of copper, $15 per pound of molybdenum, and $12 per ounce of silver, the project would generate a net present value (NPV) (5%) of approximately $1.2 billion with an internal rate of return (IRR) of 17.8% and a payback of 5 years on an after-tax basis

Announced an updated Feasibility Study. The Study re-confirms Rosemont as an economically robust open-pit copper/molybdenum mine with low development risk. Using long-term metal pricing of $1.85 per pound of copper, $15 per pound of molybdenum, and $12 per ounce of silver, the project would generate a net present value (NPV) (5%) of approximately $1.2 billion with an internal rate of return (IRR) of 17.8% and a payback of 5 years on an after-tax basis. Cash costs are estimated at $0.62 per pound of copper, net of by-product credits. Direct field cost for constructing the 75,000 ton per day open pit mine and heap-leach SX-EW facility is estimated at $712.7 million. In addition, indirect costs of $184.5 million associated with engineering, procurement and construction management, commissioning, spare parts, contingency and Owner’s costs amount to a total project capital cost of $897.2 million. The mine life based on current mineral reserves is 21 years, with cathode production commencing in Q4 2011 and concentrate production in Q1 2012.