Vancouver, Canada, June 6, 2012 - Guyana Frontier Mining Corp. (TSX-V: GYG) ("Guyana Frontier") is pleased to announce that it has carried out a review of a historical resource estimate for the Mazoa Hill deposit at the Marudi Mountain Gold Project ("Marudi Mountain") in southern Guyana, South America. The historical resource estimate was first published in 1995, prior to the implementation of National Instrument 43-101 ("N.I. 43-101"). Guyana Frontier engaged Reserva International LLC, of Reno, Nevada to conduct the review.

About the Marudi Mountain Historical Resource Estimate

The Marudi Mountain property has been the subject of extensive historical work, including approximately 28,000 metres of Diamond drilling. In June 1995, Kilborn Engineering Pacific Ltd. ("Kilborn"), of Vancouver, B.C., Canada, prepared an evaluation report (the "Evaluation Report") of Marudi Mountain for Sutton Resources Ltd ("Sutton"). The Evaluation Report included a resource estimate for the Mazoa Hill target area, where approximately 13,530 metres were drilled in 70 historical holes, based on drill core data, geological descriptions, surface trenching channel samples, and adit channel samples provided to Kilborn by Sutton. Metallurgical test data used for the Evaluation Report were taken from 1982 and 1991-1993 work programs.

Geological resources as depicted in Table 1 at selected cut-off grades of 0.50, 1.00 and 1.50 grams/tonne gold were classified by Kilborn as "Measured & Indicated", and "Inferred" categories based on the "Principles of Resources/Reserve Classification for Minerals" contained in Circular 831 published by the U.S. Bureau of Mines and the U.S. Geological Survey ("USGS"). See Table 2 for a comparison between the mineral resource category definitions described in USGS Circular 831, and those definitions published by the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") in 2010, which were adopted under N.I. 43-101.

Table1. Historical Geological Resources of the Mazoa Hill Deposit (from "Evaluation Report of the Marudi Mountain Project", by Kilborn, 1995)

Mineral Resource Category	Above Cut-off Gold Grade	Volume (m3)	Average Grade Gold	Tonnage	Metal Content (Gold)
	(grams/tonne)		(grams/tonne)	(metric tonnes)	(grams)	(oz.)
Measured & Indicated	0.50	1,584,187	2.36	4,594,143	10,842,177	348,589
Inferred	0.50	407,910	1.99	1,182,940	2,354,051	75,686
Measured & Indicated	1.00	1,165,890	2.94	3,381,081	9,940,378	319,595
Inferred	1.00	296,870	2.45	860,924	2,109,264	67,815
Measured & Indicated	1.50	906,425	3.42	2,628,633	8,989,925	289,037
Inferred	1.50	202,448	3.02	587,100	1,773,042	57,005

The resource estimate contained in the Evaluation Report is historical in nature, and is not based on an existing technical report prepared under the guidelines of N.I. 43-101. Guyana Frontier considers the historical resource estimate to be relevant to ongoing exploration and believes that it provides a conceptual indication of the potential of the gold occurrence but does not consider it to be reliable at this time. No more recent mineral resource estimate regarding the Mazoa Hill deposit is available to Guyana Frontier. A Qualified Person, as defined by the guidelines of N.I. 43-101, has not done sufficient work to classify the historical estimate as current mineral resources or mineral reserves, and Guyana Frontier is not treating the historical estimate as current mineral resources or mineral reserves.

Reserva International LLC recommends that in conjunction with additional drilling, the implementation of a comprehensive QA/QC program, standard data verification procedures, and additional measurements of specific gravity and core recovery would be required to validate the historical resource estimate and align it more closely with current best practice guidelines. Guyana Frontier has implemented industry standard QA/QC procedures in its 2012 drilling program.

As Table 2 shows below, the implementation of the CIM mineral resource category definitions presents a higher degree of detail than the definitions used prior to the implementation of N.I. 43-101. For example, the 1995 Kilborn mineral resource estimate provides a combined measured and indicated resource, and does not separate or distinguish between the two categories.

Table 2. Comparison of Mineral Resource Category Definitions, c.1995 vs. 2010

Mineral Resource Category	USGS Circular 831 (1980)	CIM (2010)
Measured Mineral Resource:	Materials whose quality and quantity have been determined, within a margin of error of less than 20 percent, by quantitative data, including appropriate analyses, from closely spaced and geologically well-known sample sites.	That part of a mineral resource for which quantity, grade or quality, densities, shape, and physical characteristics are so well established that they can be estimated with confidence sufficient to allow the appropriate application of technical and economic parameters, to support production planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough to confirm both geological and grade continuity.
Indicated Mineral Resource:	Materials whose quality and quantity have been estimated partly from analyses and measurements and partly from reasonable geologic inferences.	That part of a mineral resource for which quantity, grade or quality, densities, shape and physical characteristics can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough for geological and grade continuity to be reasonably assumed.
Inferred Mineral Resource:	Materials in identified but unexplored deposits whose quality and quantity have been estimated from geologic projections.	That part of a mineral resource for which quantity and grade or quality can be estimated on the basis of geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity. The estimate is based on limited information and sampling gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes.

Marudi Mountain 2012 Drilling Program

The 2012 drilling program was planned to assess the gold mineralization found in historical drilling and support the establishment of a N.I. 43-101 compliant resource estimate, if applicable. It is not known at this time how many drill holes or the number of metres of Diamond drilling that would be required to produce a N.I. 43-101 compliant resource estimate for the Marudi Mountain property.

Guyana Frontier's 2012 drilling program, consisting of 12 holes totaling 1,977.47 metres, concluded in April 2012 (see Guyana Frontier's news releases dated May 2, 2012 and May 24, 2012). Three holes were drilled in the Mazoa Hill target area, and the remaining 9 holes were drilled in the Marudi North target area, where Guyana Frontier had identified prospective drill targets from its extensive 2011 trenching program. Guyana Frontier successfully encountered gold mineralization at Marudi North within quartzite-metachert rocks (the host rock), interpreted as similar in composition to the rocks known to host gold mineralization at the Mazoa Hill target area, located approximately 1.6 kilometres to the south. Results of 6 holes from Marudi North yet to be reported are currently being compiled and interpreted.

For maps and photos depicting the 2012 drilling, please visit Guyana Frontier's website at www.guyanafrontier.com

The technical disclosure in this news release was reviewed and approved by Mr. Tim Carew, P.Geo., of Reserva International LLC, a Qualified Person as defined in N.I. 43-101 and an independent contractor to Guyana Frontier.

About Marudi Mountain

Marudi Mountain consists of one Mining Licence totaling 13,502 acres (5,464 hectares) located in southern Guyana approximately 500 kilometres (330 miles) from the capital city of Georgetown.

Guyana Frontier also holds the adjacent Paint Mountain property ("Paint Mountain"). Paint Mountain consists of one Prospecting Licence totaling 8,848 acres (3,581 hectares) and remains largely underexplored. Guyana Frontier recently commenced surface exploration at Paint Mountain, including trenching, prospecting, and geological mapping. A portion of the property has been selected for trenching, detailed mapping and sampling on the basis of favourable geology and the presence of artisanal alluvial gold miners. Airborne geophysical surveys are planned for both the Paint Mountain and Marudi Mountain properties in 2012.

About Guyana Frontier

Guyana Frontier is a public mineral exploration company listed on the TSX Venture Exchange (TSX-V: GYG), and is focused on the exploration, discovery and development of precious metals deposits within Guyana, South America. Guyana Frontier began acquiring interests in Guyanese exploration properties in 2007, and now holds various rights to obtain working interests in approximately 342,000 acres (138,400 hectares) of prospective lands. Guyana Frontier's goal is to develop a significant gold resource at Marudi Mountain, and to explore its other Guyanese projects using funding from exploration partners.

For further information about Guyana Frontier, please visit our website at www.guyanafrontier.com or contact Warren Stanyer, President and CEO, at (604) 558-0077.

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FORWARD LOOKING STATEMENTS

This release contains "forward-looking statements" within the meaning of applicable Canadian securities legislation. Forward-looking statements include, but are not limited to, statements that address activities, events or developments that the Company expects or anticipates will or may occur in the future, including such things as planned exploration activities at the Marudi Mountain and Paint Mountain properties, the establishment of an NI 43-101 compliant resource at the Marudi Mountain property, future business strategy, competitive strengths, goals, expansion, growth of the Company's businesses, operations, plans and with respect to exploration results, the timing and success of exploration activities generally, permitting time lines, government regulation of exploration and mining operations, environmental risks, title disputes or claims, limitations on insurance coverage, timing and possible outcome of any pending litigation and timing and results of future resource estimates or future economic studies.

Often, but not always, forward-looking statements can be identified by the use of words such as "plans", "planning", "planned", "expects" or "looking forward", "does not expect", "continues", "scheduled", "estimates", "forecasts", "intends", "potential", "anticipates", "does not anticipate", or "belief", or describes a "goal", or variation of such words and phrases or state that certain actions, events or results "may", "could", "would", "might" or "will" be taken, occur or be achieved.

Forward-looking statements are based on a number of material factors and assumptions, including, the result of drilling and exploration activities, that contracted parties provide goods and/or services on the agreed timeframes, that equipment necessary for exploration is available as scheduled and does not incur unforeseen break downs, that no labour shortages or delays are incurred, that plant and equipment function as specified, that no unusual geological or technical problems occur, and that laboratory and other related services are available and perform as contracted. Forward-looking statements involve known and unknown risks, future events, conditions, uncertainties and other factors which may cause the actual results, performance or achievements to be materially different from any future results, prediction, projection, forecast, performance or achievements expressed or implied by the forward-looking statements. Such factors include, among others, the interpretation and actual results of current exploration activities; changes in project parameters as plans continue to be refined; the existence of weather conditions suitable for exploration activities; future prices of minerals; possible variations in grade or recovery rates; failure of equipment or processes to operate as anticipated; the failure of contracted parties to perform; labour disputes and other risks of the mining industry; delays in obtaining governmental approvals or financing or in the completion of exploration, as well as those factors disclosed in the company's publicly filed documents. Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking statements, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.