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Press release from Marketwire

Revett Reports Encouraging Exploration Program at Troy Mine

Wednesday, June 23, 2010

Revett Reports Encouraging Exploration Program at Troy Mine08:00 EDT Wednesday, June 23, 2010SPOKANE VALLEY, WASHINGTON--(Marketwire - June 23, 2010) - Revett Minerals Inc. (TSX:RVM) (OTCBB:RVMIF) ("Revett" or the "Company") is pleased to announce encouraging results from its exploration program in and around the Troy Mine, including discovery of the highest grade intercept yet drilled in the "I-Beds" (24 feet of 1.99 ounces per ton silver & 0.43% copper) beneath the current mine workings.Three important features in the "I- Bed" mineralization have been illustrated in the core drilling this year. First, the intercepts in holes SL-168, SL-169 and SL-170 (500' to 800' spacing) are thicker than the previous 30 ft average of previous intercepts. The intercept in SL-169 contains 95 feet of disseminated bornite / chalcocite zone which is thicker than any intercept drilled to date in the "I-Beds", including the nearby "JF" deposit drill holes, over one mile south of the mine. The second important feature is the intercept in SL-169 with significantly higher silver grades than seen in previous drill holes below the Troy ore zones. Third, the silver/copper ratio is lower in SL-170 (42' of 0.92 opt silver & 0.37% copper) than seen in the previous "I-Bed" drilling; i.e., 2.4 vs. 3 to 4. This silver/copper ratio is closer to the historic ratio seen in the Middle Quartzite (main mining unit) at Troy and for the mineralization at the Rock Creek project. The new drilling in 2010 indicates that the "I-Bed" mineralization is thickening and may be of better quality to the south and west of the previously drilled mineralization below the current Troy ore bodies.Hole SL-170 also contained an intercept in the Lower Quartzite (22 feet of 0.87 opt silver & 0.35% copper). This encouraging mineralization is being followed up by several short delineation core holes. This intercept may be an eastern extension of the ore currently being mined in the South Ore Body Lower Quartzite which could likely be developed in the short term to supplement current production. John Shanahan, Revett's President/CEO stated "We are very pleased to announce that results from underground core drilling have confirmed the presence of a thicker, higher grade area within the "I-Beds", approximately 1,120 feet below the current operations at Troy. Based on our increasing confidence in delineating a significant resource in the "I-Beds" we are looking to accelerate the exploration efforts at Troy. We believe continued exploration success, such as experienced with the C-Bed discovery and development, will add significantly to Troy's mine life and facilitate the eventual development of the JF Properties to the south. Troy continues to provide an important environmental and economic baseline for development plans at Rock Creek." Troy Exploration Program Revett began exploring at Troy in 2006 to follow up on a prospective regional program performed by prior owner ASARCO Inc. While the primary near-term focus has been to further delineate the extensive stratabound copper and silver mineralization hosted in the "I-Beds" of the Lower Revett Formation beneath and adjacent to our current workings (approx.1,120 feet below mine workings), we will also follow up on new geologic interpretations which resulted in the discovery of the "C-Bed" ore body (1.8 M tons of 1.61opt Ag & 0.56% Cu, as disclosed in the Company's 2010 10-K) which we are currently developing. The ultimate goal of this phase of the program is to demonstrate mineralization continuity in the "I-Beds" starting from beneath the active mine south for approximately 8,000 feet to the "I-Bed" hosted "JF" deposit (Historical Resource of "11 million tons grading 0.4% Cu and 1.4 opt Ag"). If this phase is successful in defining a mineable project, we envision accessing the "I-Beds" (including the "JF") as we continue development vertically downward to augment and extend our current six year mine plan. If successful, the Troy mine life could more than double assuming current extraction rates.Longer term, we believe the geologic potential around the active Troy Mine is excellent and have been systematically increasing our property holdings around the mine through both staking and acquiring claims covering the known mineralized trends to the north and east of the mine. Revett's intention is to delineate, and bring into production, deposits in the area in which we can utilize the existing milling capacity at Troy. We will carry out this phase over the next several years through geologic mapping, geophysics, and core drilling to advance these early stage targets towards production.Revett Formation The Revett Formation consists of three main strata units, the Upper, Middle and Lower. The main Troy mining areas are currently located in the Upper Revett unit. Other mineralization occurs in the Lower Revett in a series of bedding units labeled "A" through "I" stratigraphically downward. Drilling from both underground and surface programs have intercepted strata-bound copper/silver mineralization in the "A, B, C and I- Beds" of the Lower Revett Formation, ranging from 180 to 1,120 feet below the Troy workings. The Company's Rock Creek project is also hosted in the Lower Revett Formation, specifically the "A, C & E-Beds", and the Company has confirmed the presence of ore grade mineralization in the "A, C & I- Beds" at Troy. Lower Revett Formation "A-Bed" Drill Results Depth below Mine Workings: 180'. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- From To Drill Interval Silver Copper Hole ID (feet) (feet) (feet) Grade Grade Date/Company ---------------------------------------------------------------------------- SL-150 362' 392' 30' 0.38 opt 0.21% 2006/Revett SL-152 373' 416' 43' 0.66 opt 0.14% 2006/Revett SL-153 366.5' 411' 44.5' 1.11 opt 0.25% 2007/Revett SL-154 358' 406' 44' 0.46 opt 0.24% 2007/Revett SL-155 414' 428' 14' 0.39 opt 0.29% 2007/Revett SL-156 384' 412' 28' 0.93 opt 0.28% 2007/Revett SL-158 394' 422' 28' 0.47 opt 0.20% 2007/Revett SL-159 413' 435' 22' 0.36 opt 0.21% 2007/Revett SL-160 449' 459' 10' 0.87 opt 0.43% 2007/Revett SL-168 356' 386' 28' 0.85 opt 0.29% 2010/Revett SL-169 361.5' 381.5' 20' 0.64 opt 0.22% 2010/Revett ---------------------------------------------------------------------------- Lower Revett Formation "B-Bed" Drill Results Depth below Mine Workings: 325'. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- From To Drill Interval Silver Copper Hole ID (feet) (feet) (feet) Grade Grade Date/Company ---------------------------------------------------------------------------- SL-154 550.5' 578' 27.5' 1.35 opt 0.65% 2007/Revett SL-155 501' 517' 16' 0.51 opt 0.20% 2007/Revett ---------------------------------------------------------------------------- Lower Revett Formation "C-Bed" Drill Results Depth below Mine Workings: 370'. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- From To Drill Interval Silver Copper Hole ID (feet) (feet) (feet) Grade Grade Date/Company ---------------------------------------------------------------------------- SL-154 584' 620' 36' 1.68 opt 0.57% 2007/Revett SL-155 568' 598' 30' 1.50 opt 0.59% 2007/Revett SL-158 554' 576' 22' 2.09 opt 0.63% 2007/Revett SL-159 581' 613' 32' 1.37 opt 0.47% 2007/Revett including 16' 1.79 opt 0.62% SL-160 557' 567' 10' 0.37 opt 0.18% 2007/Revett ---------------------------------------------------------------------------- Lower Revett Formation "I-Bed" Drill Results Depth below Mine Workings: 1,120'. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- From To Drill Interval Silver Copper Hole ID (feet) (feet) (feet) Grade Grade Date/Company ---------------------------------------------------------------------------- SL-125 1,312' 1,330' 18' 0.62 opt 0.18% 1987/ASARCO SL-126 1,888' 1,900' 12' 0.66 opt 0.28% 1987/ASARCO SL-131 907' 918' 11' 1.02 opt 0.41% 1989/ASARCO SL-150 1,279' 1,315' 36' 1.09 opt 0.21% 2006/Revett SL-151 1,346' 1,366' 20' 0.57 opt 0.22% 2006/Revett SL-152 1,302.5' 1,317.5' 28.5' 0.79 opt 0.18% 2006/Revett SL-153 1,314' 1,337' 23' 1.48 opt 0.24% 2007/Revett SL-154 1,338' 1,364' 26' 0.71 opt 0.22% 2007/Revett SL-155 1,345' 1,380' 35' 0.79 opt 0.24% 2007/Revett SL-156 1,325' 1,345' 20' 0.85 opt 0.28% 2007/Revett SL-158 1,334' 1,368' 34' 0.53 opt 0.23% 2007/Revett SL-159 1,417' 1,439' 22' 0.61 opt 0.23% 2007/Revett SL-160 1,499' 1,523' 24' 0.09 opt 0.15% 2007/Revett SL-161 1,029' 1,059' 30' 0.73 opt 0.32% 2007/Revett SL-162 1,120' 1,152' 32' 0.70 opt 0.23% 2007/Revett SL-163 1,378' 1,392' 14' 0.16 opt 0.01% 2007/Revett SL-165 1,181' 1,185' 4' 1.47 opt 0.87% 2008/Revett SL-168 1,286' 1,334' 48' 0.86 opt 0.29% 2010/Revett SL-169 1,306' 1,346' 40' 1.64 opt 0.37% 2010/Revett including 24' 1.99 opt 0.43% 2010/Revett SL-170 1,342' 1,384' 42' 0.92 opt 0.37% 2010/Revett including 20' 1.04 opt 0.43% 2010/Revett ---------------------------------------------------------------------------- Note: Holes SL-125 through SL-159 were previously released. Assay Quality Assurance/Quality ControlCore samples were collected under the direct supervision of Revett personnel and stored at a secure storage facility at the Troy Mine. Detailed geologic logging identified the mineralized intervals sampled. All the samples were taken from NC cores (approx.2") that were sawed in half. In general two foot intervals were sampled. All samples were analyzed for copper, silver and lead using atomic absorption spectrometry. Any samples with silver values greater than 0.40 ounces per ton were fire assayed. A total of 1802 samples were taken from intercepts in drill holes SL-150 through SL-170.Revett has submitted reference samples to American Analytical Services and Chris Christopherson Inc. for Quality Assurance /Quality Control. Typical ore grade material and mine tailing (waste) material are used as reference samples. Approximately one in twenty samples is a reference sample and 10% of the core sample results are checked at the Genesis-Troy Mine lab. Larry Erickson, an employee of Revett and a Qualified Person ("QP"), has verified the data relating to the results of drilling disclosed in this press release and has reviewed the contents of the press release.About RevettRevett Minerals, through its subsidiaries, owns and operates the currently producing Troy Mine in Lincoln County, Montana and development-stage Rock Creek Project located in Sanders County, Montana, USA. The proven reserves at the Troy Mine and significant resources at the Rock Creek project will form the basis of our plan to become a solid mid-tier base and precious metals producer. Revett plans on expanding production through exploration in and around its current properties, as well as through targeted business combinations of advanced stage projects.John Shanahan, President & CEO This press release contains forward-looking statements regarding the Company's plan to undertake an extensive exploration program in the Troy Complex and the Company's expectation that the exploration will add significantly to Troy's mine life and could more than double assuming current extraction rates and facilitate the eventual development of the JF Properties. The exploration program will be dependant upon obtaining the required permits and the Company's ability to continue funding the program. The forward-looking statements contained in this press release represent the Company's views and expectations as of the date of this press release and should not be relied upon as representing the Company's views and expectations as of a subsequent date.In addition, the historical resource identified for the JF deposit was determined using information obtained by the Company from ASARCO and such information has not been verified by the Company as to its accuracy. In 1992, ASARCO reported in an internal report a "Mineral Reserve" for the "JF" deposit of "11 million tons grading 0.4% Cu and 1.4 opt Ag." This historical mineral resource estimate, which was prepared before the adoption of NI 43-101 and uses categories other than the ones set out in section 1.2 of NI 43-101, is considered relevant. A QP has not, however, done sufficient work to classify the historical estimate as current mineral resources and accordingly, Revett does not treat ASARCO's historical estimate as current mineral resources. The reader is cautioned that the ASARCO historical estimate should not be relied upon.FOR FURTHER INFORMATION PLEASE CONTACT: Revett Minerals Inc. Monique Hayes Director of Corporate Communications (509) 921-2294 or Revett Minerals Inc. Doug Ward VP Corporate Development (509) 921-2294