Trevali Increases Inferred Resources by 188% to 13.84 Million Tonnes at Santander Zinc-Lead-Silver Mine Project in Peru-Provides Corporate Update

VANCOUVER, BRITISH COLUMBIA--(Marketwire - July 5, 2012) - Trevali Mining Corporation ("Trevali" or the "Company") (TSX:TV)(TSX:TV.WT)(LMA:TV)(OTCQX:TREVF)(FRANKFURT:4TI) is pleased to announce the results of its 2012 independent National Instrument 43-101 mineral resource estimate update for the Santander zinc-lead-silver mine project in west-central Peru. The 2011 drill program successfully defined an additional inferred resource of 9.04 million tonnes at a 3% ZnEQ* cut-off, beneath the 2010 Magistral Central and South deposits and within the formerly-producing Santander Pipe deposit (Table 1 & Figure 1).

Resource Category	Cutoff ZnEQ (%)*	Million Tonnes	Grade					Contained Metal
			Ag (g/t)	Pb (%)	Zn (%)	Cu (%)	ZnEQ (%)*	Ag (M t.oz)	Pb (M lbs)	Zn (M lbs)	Cu (M lbs)
Indicated	1.00	8.544	35	1.06	3.05	0.06	4.92	9.613	200.258	574.066	11.523
	2.00	7.609	38	1.16	3.29	0.07	5.34	9.354	193.803	552.595	11.162
	3.00	6.264	43	1.30	3.62	0.07	5.95	8.740	179.734	500.218	10.199
	4.00	4.844	50	1.49	3.98	0.08	6.67	7.786	158.638	425.203	8.734
	5.00	3.556	58	1.70	4.34	0.09	7.46	6.592	133.510	340.513	7.013
Inferred	1.00	22.511	18	0.32	3.42	0.09	4.00	12.987	156.602	1,696.071	42.334
	2.00	18.065	20	0.36	3.99	0.10	4.62	11.496	142.313	1,589.804	39.263
	3.00	13.845	21	0.40	4.62	0.11	5.27	9.373	121.089	1,410.485	34.900
	4.00	10.145	23	0.45	5.24	0.13	5.93	7.346	101.423	1,171.555	28.699
	5.00	6.612	24	0.54	5.92	0.15	6.70	5.207	78.885	862.537	21.149
Table 1: 2012 Capped Indicated and Inferred Mineral Resources at Santander Project after Golder Associates Ltd.

To view Figure 1, please visit: http://media3.marketwire.com/docs/tv705_F1.pdf.

The 10,000-metre 2011 Resource Expansion drill program focused almost exclusively on expanding the down-dip extensions of the Magistral deposits as well as confirmation drilling on the formerly-producing Santander Pipe where mineral system analysis and 3D modeling suggested that significant tonnages may be present (Figure 2).

To view Figure 2, please visit: http://media3.marketwire.com/docs/tv705_F2.pdf.

"Since the initial discovery hole in early 2008, our exploration team has consistently delivered for the Company and continues to validate our belief in the significant exploration potential of the Santander project. We now have one of the larger undeveloped zinc-rich polymetallic systems in the Tier 1 Central Peruvian Mineral Belt and we continue to rank the exploration potential good-to-excellent and low-to-moderate risk - essentially everything remains open for expansion. We have identified 17 kilometres of permissive mineral fairway of which only approximately 800-900 metres has been drill tested. Consequently, we feel the odds of expanding the current upgraded resource and discovering new zones of mineralization going forward remain high," stated Dr. Mark Cruise, Trevali's President and CEO. "Furthermore, this dramatic increase in mineralization forms an excellent foundation for Trevali's plans to potentially double production in the short-to-medium term following final construction and commissioning of our initial 2,000-tonne-per-day processing plant later this year."

DETAILS

The updated resource estimate is based on 190 drill holes (42,000.8 metres), 109 sawn-channel samples (1,819.56 metres) and 10,585 geochemical assays in addition to 318 historic drill holes (18,507.29 metres), 947 historic channel samples (5,245.55 metres) and 7,812 historic assays for the Santander Pipe deposit. The resource estimate was conducted by and under the supervision of Greg Greenough P.Geo., an independent qualified person and Senior Resource Geologist at Golder Associates Ltd. ("Golder") of Mississauga, Canada, and utilized a 3% ZnEQ* cut-off-grade - which is the nominal base-case estimated grade of material that can be mined and processed considering all applicable costs. The mineral resources identified in Tables 1 and 2 are based on Ordinary Kriged (OK) capped values.

In detail, Trevali's 2011 drill campaign successfully defined an additional 3.94 million new inferred tonnes (3% ZnEQ* cut-off) within the Magistral Central-South deposits where drilling confirmed that the two deposits merge at depth (Figure 3). The new global estimated inferred tonnage for the Magistral deposits has now increased to 5.41 million tonnes with an average grade of 4.44% zinc, 22 g/t silver, 0.47% lead and 0.08% copper at 3% ZnEQ* cut-off - an increase of 269% (Table 2).

To view Figure 3, please visit: http://media3.marketwire.com/docs/tv705_F3.pdf.

Drilling and reconciliation studies also confirmed the presence of significant mineralization within the historically-mined Santander Pipe resulting in the addition of 5.08 million inferred tonnes at 3% ZnEQ* cut-off. Total inferred tonnage defined to date in the Santander Pipe is 8.4 million tonnes with an average grade of 4.75% zinc, 20 g/t silver, 0.34% lead, and 0.14% copper at 3% ZnEQ* cut-off or an increase of 153% compared with the 2010 NI 43-101 Resource Estimate (Table 2).

The Company believes that there is significant remaining exploration potential peripheral to and below the currently defined Santander Pipe resource and future drill programs will seek to expand upon this newly defined resource.

Table 2: July 2012 Resource Estimate by deposit

Magistral Central and South - Combined
Resource Category	Cutoff ZnEQ (%)*	Million Tonnes	Grade					Contained Metal
			Ag (g/t)	Pb (%)	Zn (%)	Cu (%)	ZnEQ (%)*	Ag (M t.oz)	Pb (M lbs)	Zn (M lbs)	Cu (M lbs)
Indicated	1.00	5.270	28	0.44	3.43	0.06	4.43	4.767	51.250	398.994	7.251
	2.00	4.637	31	0.47	3.74	0.07	4.83	4.601	48.277	382.493	6.986
	3.00	3.691	35	0.52	4.18	0.08	5.42	4.183	42.514	340.509	6.314
	4.00	2.738	40	0.59	4.67	0.09	6.09	3.565	35.346	281.846	5.276
	5.00	1.884	47	0.65	5.19	0.10	6.82	2.820	27.096	215.508	4.026
Inferred	1.00	9.006	18	0.19	3.12	0.06	3.56	5.103	37.950	618.817	11.484
	2.00	6.635	20	0.21	3.85	0.07	4.30	4.226	31.029	562.806	10.033
	3.00	4.792	20	0.22	4.62	0.08	5.00	3.109	23.159	488.276	8.373
	4.00	3.431	21	0.23	5.28	0.09	5.62	2.327	17.427	399.012	6.683
	5.00	2.149	23	0.24	5.93	0.10	6.27	1.598	11.423	280.945	4.681

Magistral North**
Resource Category	Cutoff ZnEQ (%)*	Million Tonnes	Grade					Contained Metal
			Ag (g/t)	Pb (%)	Zn (%)	Cu (%)	ZnEQ (%)*	Ag (M t.oz)	Pb (M lbs)	Zn (M lbs)	Cu (M lbs)
Indicated	1.00	2.789	50	2.23	2.61	0.07	6.17	4.483	136.874	160.343	4.195
	2.00	2.675	52	2.29	2.68	0.07	6.37	4.455	135.315	158.303	4.126
	3.00	2.355	57	2.47	2.89	0.07	6.90	4.311	128.425	149.905	3.848
	4.00	1.964	64	2.69	3.15	0.08	7.58	4.042	116.629	136.329	3.435
	5.00	1.592	72	2.91	3.44	0.08	8.29	3.662	101.989	120.648	2.974
Inferred	1.00	1.061	29	1.83	2.10	0.06	4.63	0.988	42.872	49.158	1.323
	2.00	0.877	33	2.06	2.42	0.06	5.27	0.932	39.849	46.716	1.216
	3.00	0.618	40	2.45	3.04	0.07	6.45	0.802	33.446	41.486	1.019
	4.00	0.480	46	2.72	3.54	0.08	7.33	0.705	28.777	37.498	0.878
	5.00	0.403	49	2.86	3.88	0.08	7.87	0.637	25.442	34.442	0.752

Puajanca South**
Resource Category	Cutoff ZnEQ (%)*	Million Tonnes	Grade					Contained Metal
			Ag (g/t)	Pb (%)	Zn (%)	Cu (%)	ZnEQ (%)*	Ag (M t.oz)	Pb (M lbs)	Zn (M lbs)	Cu (M lbs)
Indicated	1.00	0.486	23	1.13	1.38	0.01	3.05	0.362	12.134	14.729	0.077
	2.00	0.297	31	1.56	1.80	0.01	4.08	0.298	10.211	11.798	0.050
	3.00	0.219	35	1.82	2.03	0.01	4.66	0.247	8.796	9.804	0.036
	4.00	0.142	39	2.13	2.24	0.01	5.27	0.179	6.664	7.028	0.023
	5.00	0.081	42	2.49	2.45	0.01	5.90	0.110	4.424	4.357	0.012
Inferred	1.00	0.625	12	0.49	1.20	0.01	1.90	0.232	6.771	16.575	0.116
	2.00	0.261	16	0.67	1.65	0.01	2.61	0.135	3.889	9.518	0.051
	3.00	0.026	30	1.92	1.77	0.01	4.36	0.025	1.079	0.998	0.005
	4.00	0.017	31	2.24	2.02	0.01	4.92	0.017	0.850	0.767	0.003
	5.00	0.008	35	2.34	2.38	0.01	5.43	0.009	0.421	0.429	0.001

Santander Pipe***
Resource Category	Cutoff ZnEQ (%)*	Million Tonnes	Grade					Contained Metal
			Ag (g/t)	Pb (%)	Zn (%)	Cu (%)	ZnEQ (%)*	Ag (M t.oz)	Pb (M lbs)	Zn (M lbs)	Cu (M lbs)
Indicated	1.00	-	-	-	-	-	-	-	-	-	-
	2.00	-	-	-	-	-	-	-	-	-	-
	3.00	-	-	-	-	-	-	-	-	-	-
	4.00	-	-	-	-	-	-	-	-	-	-
	5.00	-	-	-	-	-	-	-	-	-	-
Inferred	1.00	11.820	18	0.26	3.88	0.11	4.40	6.663	69.009	1,011.520	29.411
	2.00	10.291	19	0.30	4.28	0.12	4.83	6.203	67.546	970.765	27.962
	3.00	8.409	20	0.34	4.75	0.14	5.35	5.438	63.405	879.725	25.503
	4.00	6.217	21	0.40	5.36	0.15	6.00	4.296	54.369	734.278	21.134
	5.00	4.052	23	0.47	6.12	0.18	6.81	2.963	41.598	546.722	15.715

* ZnEQ = ((Ag Price(g) x Ag Recovery x Ag Grade) + (Pb Price(t) x Pb Recovery x (Pb Grade(%)/100)+(Zn Price(t) x Zn Recovery x (Zn Grade(%)/100)))/Zn Price(t). Golder utilized the US dollar three year rolling average price for all three metals. Price for silver is ($25.99/oz) and that for Pb ($2,205), Zn ($2,094) and Cu ($7,782) is per tonne. A recovery of 85% was applied to Ag, 90% for Pb, 85% for Zn and 60% for Cu for calculating the ZnEQ formula. The pounds of metal are in-situ and have not had any mining factors applied to them.

** Resource estimates for Magistral North and Puajanca South are unchanged from 2010 but have been updated to reflect 2012 metal prices.

*** The Santander Pipe resource contains two distinct components, material below 4,015 m elevation which has not been mined and material above 4,015 m elevation which is adjacent to former mine infrastructure (Figure 4). At the 3% ZnEQ cut-off, material below 4,015 m elevation accounts for 2.691 M tonnes at 14 g/t Ag, 0.06% Pb, 0.08% Cu and 5.45% Zn, and material above 4,015 m elevation accounts for 5.718 M tonnes at 23 g/t Ag, 0.48% Pb, 0.17% Cu and 4.41% Zn.

To view Figure 4, please visit: http://media3.marketwire.com/docs/tv705_F4.pdf.

CORPORATE UPDATE

CHIEF OPERATING OFFICER

Trevali is pleased to announce the appointment of Mr. Paul Keller, P.Eng, as Chief Operating Officer. Mr. Keller joined Trevali in May 2011 as Vice-President Operations and has been instrumental in the permitting and construction of the Company's Halfmile Mine and oversight of its Santander project. Mr. Keller has over 28 years of extensive mine operations experience in Canada. Prior to joining Trevali, he was Manager of Technical Services for a major Canadian mining contractor where he led a team of engineers and designers on various mining contracts for major mining companies. Mr. Keller began his career with Rio Algom Limited and has also worked in various management roles with Barrick Gold's Hemlo mine in operations, engineering and maintenance. Mr. Keller holds a Bachelor of Engineering/Mining from Laurentian University and is a Professional Engineer.

WORKING CAPITAL LINE OF CREDIT

Trevali Mining Corporation is also pleased to announce that it has entered into an agreement with Auramet Trading LLC for a receivables working capital line of credit of US$5 million. Trevali intends to use the facility to support the Company's Halfmile mining activities and for general corporate purposes. Auramet, based in Fort Lee, New Jersey, is a leading metals trading, merchant banking and advisory firm specializing in the global resource sector.

ABOUT TREVALI MINING CORPORATION

Trevali is a zinc-focused base metals producer with operations in Canada and Peru - the Halfmile and Santander mines, respectively. In Canada, Trevali owns the Halfmile zinc-lead-silver mine and Stratmat polymetallic deposit and has entered into a definitive agreement to acquire the Caribou Mine and Mill, all located in the Bathurst Mining Camp of northern New Brunswick. The Company also has the past-producing Ruttan copper-zinc mine in northern Manitoba. Production from the Halfmile mine commenced in early 2012 and is ramping up to the planned production rate of 2,000-tonnes-per-day.

In Peru, the Company has the Santander zinc-lead-silver mine and the former-producing Huampar silver mine, both located in the Central Peruvian Polymetallic Belt. Mine commissioning is anticipated to commence at the Santander operation in late-2012 with ramp up to full 2,000-tonnes-per-day production to follow shortly thereafter. Additionally, through its wholly-owned subsidiary (Trevali Renewable Energy Inc.), Trevali is undertaking a significant upgrade of its wholly-owned Tingo run-of-river hydroelectric generating facility along with transmission line upgrades and extensions to allow the supply of power to the mining operation on the property, as well as the potential sale of surplus power into the Peruvian National Energy Grid.

The common shares of Trevali are listed on the TSX (symbol TV), the OTCQX (symbol TREVF) and on the Lima Stock Exchange (symbol TV). Warrants to purchase common shares of Trevali are listed on the TSX (symbol TV.WT). For further details on Trevali, readers are referred to the Company's web site (www.trevali.com) and to Canadian regulatory filings on SEDAR at www.sedar.com.

Qualified Person and Quality Control/Quality Assurance

EurGeol Dr. Mark D. Cruise, Trevali's President and CEO and a qualified person as defined by National Instrument 43-101, has supervised the preparation of the scientific and technical information that forms the basis for this news release. Dr. Cruise is not independent of the Company, as he is an officer and shareholder.

The work programs at Santander were designed and supervised by, Mark D. Cruise, President & CEO, Trevali, Tim Kingsley (Senior Geologist) and Tansy O'Connor-Parsons (Chief Geochemist), who together are responsible for all aspects of the work, including the quality control/quality assurance programs. On-site personnel at the project rigorously collect and track samples which are then security sealed and shipped to ACME Laboratories, Vancouver, for assay. ACME's quality system complies with the requirements for the International Standards ISO 9001: 2000 and ISO 17025: 1999. Analytical accuracy and precision are monitored by the analysis of reagent blanks, reference material and replicate samples. Quality control is further assured by the use of international and in-house standards. Blind certified reference material is inserted at regular intervals into the sample sequence by Trevali personnel in order to independently assess analytical accuracy. Finally, representative blind duplicate samples are routinely forwarded to ACME and an ISO compliant third party laboratory for additional quality control.

On Behalf of the Board of Directors of TREVALI MINING CORPORATION

Mark D. Cruise, President

This news release contains "forward-looking statements" within the meaning of the United States private securities litigation reform act of 1995 and "forward-looking information" within the meaning of applicable Canadian securities legislation. Statements containing forward-looking information express, as at the date of this news release, the Company's plans, estimates, forecasts, projections, expectations, or beliefs as to future events or results and the company does not intend, and does not assume any obligation to, update such statements containing the forward-looking information. Such forward-looking statements and information include, but are not limited to statements as to: the accuracy of estimated mineral reserves and resources, anticipated results of future exploration, and forecast future metal prices, anticipated results of future electrical sales and expectations that environmental, permitting, legal, title, taxation, socio-economic, political, marketing or other issues will not materially affect estimates of mineral reserves. These statements reflect the Company's current views with respect to future events and are necessarily based upon a number of assumptions and estimates that, while considered reasonable by the Company, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies.

These statements reflect the Company's current views with respect to future events and are necessarily based upon a number of assumptions and estimates that, while considered reasonable by the company, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements contained in this news release and the company has made assumptions and estimates based on or related to many of these factors. Such factors include, without limitation: fluctuations in spot and forward markets for silver, zinc, base metals and certain other commodities (such as natural gas, fuel oil and electricity); fluctuations in currency markets (such as the Peruvian sol versus the U.S. dollar); risks related to the technological and operational nature of the Company's business; changes in national and local government, legislation, taxation, controls or regulations and political or economic developments in Canada, the United States, Peru or other countries where the Company may carry on business in the future; risks and hazards associated with the business of mineral exploration, development and mining (including environmental hazards, industrial accidents, unusual or unexpected geological or structural formations, pressures, cave-ins and flooding); risks relating to the credit worthiness or financial condition of suppliers, refiners and other parties with whom the Company does business; inadequate insurance, or inability to obtain insurance, to cover these risks and hazards; employee relations; relationships with and claims by local communities and indigenous populations; availability and increasing costs associated with mining inputs and labour; the speculative nature of mineral exploration and development, including the risks of obtaining necessary licenses and permits and the presence of laws and regulations that may impose restrictions on mining,; diminishing quantities or grades of mineral reserves as properties are mined; global financial conditions; business opportunities that may be presented to, or pursued by, the Company; the Company's ability to complete and successfully integrate acquisitions and to mitigate other business combination risks; challenges to, or difficulty in maintaining, the Company's title to properties and continued ownership thereof; the actual results of current exploration activities, conclusions of economic evaluations, and changes in project parameters to deal with unanticipated economic or other factors; increased competition in the mining industry for properties, equipment, qualified personnel, and their costs. Investors are cautioned against attributing undue certainty or reliance on forward-looking statements.

Although the Company has attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated, described or intended. The Company does not intend, and does not assume any obligation, to update these forward-looking statements or information to reflect changes in assumptions or changes in circumstances or any other events affecting such statements or information, other than as required by applicable law.

Trevali's production plans at Halfmile-Stratmat and Santander are based only on Indicated and Inferred Mineral Resources and not Mineral Reserves and do not have demonstrated economic viability. Inferred Mineral Resources are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as Mineral Reserves, and there is therefore no certainty that the conclusions of the production plans and Preliminary Economic Assessment (PEA) will be realized. Additionally where Trevali discusses exploration/expansion potential, any potential quantity and grade is conceptual in nature and there has been insufficient exploration to define a mineral resource and it is uncertain if further exploration will result in the target being delineated as a mineral resource.