MacDonald Mines Releases Final Assays From James Bay; Identifies Fourth Limb on Potential Matagami-Type VMS Camp

TORONTO, ONTARIO--(Marketwire - June 22, 2010) - MacDonald Mines Exploration (TSX VENTURE:BMK) ("MacDonald" or "the Company") announces the results from the spring 2010 drill program on its McNugget Property located in the Ring of Fire, James Bay Lowlands.

The 26 hole, 4,471 meter drill program consisted of a series of holes designed to test electromagnetic ("EM") anomalies on three fold limbs associated with sequences containing volcanogenic massive sulphide (VMS) mineralization of substance (as described by Hadyn R. Butler, P.Geo) and having characteristics similar to the Matagami or Noranda VMS camps in Quebec, where larger VMS deposits with satellite deposits along strike were found. This conclusion is also supported by C. Tucker Barrie PhD, P.Geo who, accompanied by the Company's Vice President of Exploration Quentin Yarie, P.Geo, has just completed a comprehensive on-site review of previous nickel and VMS drill core and exploration data. The historical production and resource from the Matagami Camp was 25 million tonnes grading 0.56% copper, 8.2% zinc and 20.91 g/t silver.

The Company is very encouraged by this large VMS system which is open in all directions and yields VMS mineralization over a potential cumulative strike length of approximately 20 kilometres. Upcoming drilling will focus on finding the best economic intersections along the VMS horizons. As noted in the Company's recent news releases, many other EM targets found during this winter/spring's revised data compilation will also be subject to follow-up prior to drill target selection.

Assay Highlights

Highlighted base metal results from this completed phase of drilling are summarized in tables at the end of this release with full assay results available at www.macdonaldmines.com. A summary of these highlighted drill holes are as follows and note that holes MN10-102 and MN10-104 contain copper, zinc and silver values within the same intersection.

• Hole MN10-102 intersected 1.03% over 15 metres
• Hole MN10-111 intersected 1.04% over 5 metres
• Hole MN10-90 intersected 1.11% over 5 metres

• Hole MN10-104 intersected 3.3% over 9 metres
• Hole MN10-106 intersected 2.55% over 4 metres
• Hole MN10-110 intersected 2.82% over 5 metres
• Hole MN10-102 intersected 2.5% over 3 metres
• Hole MN10-104 intersected 2.00% Zn and 0.88% Cu over 6 metres

• Hole MN10-87 intersected 13.32 g/t over 5.3 metres
• Hole MN10-94 intersected 16.57 g/t over 4 metres
• Hole MN10-102 intersected 11.67 g/t over 3 metres
• Hole MN10-104 intersected 11.97 g/t over 3 metres

Crone Geophysics Interprets Fourth VMS-Mineralized Limb

On-going data compilation has established that a fourth mineralized fold limb occurs on the McNugget Property striking southeast. During the spring work program, MacDonald surveyed previous drill holes on the fourth limb with the Crone Geophysics down hole pulse EM system. This technique proved invaluable at locating targets that were unexplained in previous exploration programs. This approach was used to locate borehole MN10-104.

MN06-18 and MN06-17 (drilled in 2006) were also geophysically probed. The interpretation of these data suggests a target with similar characteristics as those of MN10-104 – a conductive, steeply dipping sheet. Based on the borehole geophysics, a surface EM survey is being completed over the target (to be drilled during the next phase of exploration).

Quentin Yarie, P. Geo, Vice President of Exploration comments, "This target on the newly identified fourth mineralized fold limb was not previously seen by the earlier VTEM survey. The conductance is quite high and it appears to have some strike length with the top of it being rich in Zn, followed by Cu. We are in the process of mapping it, as we know the results from MN06-17 had significant Zn and silver (Ag) numbers".

MN06-18 intersected 6.99m of 0.59% Cu, 2.70% Zn, 17.59 g/t Ag including a 2.79m intersection of 5.21% Zn. Of particular interest in this hole is the build up to a late time, long wavelength off-hole anomaly representing a deeper conductor which has never been tested. This represents an exciting new target and preliminary modeling results indicate the potential here for a large, high conductance source. MN06-18 is located approximately 700m east of the "North Fold limb" noted in Macdonald's press release dated 5/31/2010.

Nickel Target Identified on MacDonald and Hawk Uranium Joint Venture Ground

MacDonald Mines has completed a surface Crone Geophysics Pulse EM survey over a highly prospective nickel (Ni) target in the vicinity of borehole MN06-39 (27m averaging 0.17% Ni including 1m intersections of > 0.5% Ni). Preliminary interpretation indicates a step response of a conductive body trending approximately East-West with a strike length of over 300m which is currently being modeled. A second conductor may exist under one of the loop edges. The surface program is being widened with a different transmitter loop location to assist in the resolution of both conductors prior to drilling of this target in the summer of 2010.

Further assay results

Fire assays for gold (Au) content are pending on all holes drilled during the spring program.

On-site Quality Assurance/Quality Control Measures

All diamond drill (half core) samples were collected and sealed on site and shipped under chain of custody supervision to the ACTLABS sample preparation laboratory in Thunder Bay, Ontario. Analyses are performed by ACTLABS laboratories (ISO/IEC 17025 certified) either in Ancaster or Thunder Bay, Ontario. All core samples were selected by the MacDonald Mines qualified site geologist, and were cut in half on site by diamond saw. For security, the remaining half core was then resealed in the original core boxes. Individual half core samples were labelled, placed in plastic sample bags and sealed. Groups of samples were placed into sealed and durable rice bags then shipped out by air transport. Remaining coarse reject portions of all samples remain in storage at the ACTLABS preparation laboratory storage facility at Thunder Bay.

Independent Quality Assurance and Quality Control Protocol

A QA/QC program has been implemented to monitor all assays from the current drilling program. Samples are assembled as batches and are continuously shipped from the site for immediate testing. Included in each batch of samples are certified reference standards (every 20 samples) and blank samples comprised of sterile drill core placed in at random locations (every 20-30 samples).

Quentin Yarie, P.Geo, Vice President of Exploration is the qualified person for the technical data contained within this report.

The following table identifies the highlighted Copper (Cu) and Zinc (Zn) values for the drill holes completed to date.

Please note that 10,000 ppm (parts per million) equals 1%, or 1 ppm equals 1 g/t.

Highlighted Copper Results

About MacDonald Mines Exploration Inc.

MacDonald Mines is a mineral exploration company with an established history in the exploration of gold and base metals. MacDonald has set upon a strategic direction of exploration in the Canadian Northlands, with particular focus on the "Ring of Fire" in James Bay, Ontario. More detailed information is available on the website at www.macdonaldmines.com.

Cautionary Statement:

The foregoing information may contain forward-looking statements relating to the future performance of MacDonald Mines Exploration Inc. Forward-looking statements, specifically those concerning future performance, are subject to certain risks and uncertainties, and actual results may differ materially from MacDonald Mines plans and expectations. These plans, expectations, risks and uncertainties are detailed herein and from time to time in the filings made by MacDonald Mines with the TSX Venture Exchange and securities regulators. MacDonald Mines does not assume any obligation to update or revise its forward-looking statements, whether as a result of new information, future events or otherwise.