MICREX DEVELOPMENT CORP.

A mineral exploration and development company operating in Canada and the United States

TSX Venture Exchange symbol "MIX"
SEC 12 g (3) Exemption 82-4281

For immediate release

May 17, 2007

Micrex Begins Geophysics Program at Bighorn

Micrex Development Announced today that airborne geophysics has begun at the Bighorn Project in Northern British Columbia.

Fugro Airborne Surveys will be carrying out the program using a helicopter mounted sensor system. This 74 square kilometer program has been designed to support this year’s ground based exploration effort.

Previous work on the property has identified mineralization and structures that Micrex hopes to further delineate with this program.

This geophysics program was paid for and scheduled in 2006 but weather and aircraft availability became factors and the program was rescheduled for the spring of 2007.

Micrex considers the Bighorn to be an important exploration target. Limited mining was carried out at Bighorn between 1921 and 1935 on a single quartz vein. The gold bearing vein, called the Lawson Vein, has been traced for a strike length of 920 m. (2990 ft.) and a vertical distance over 460 m. (1495 ft.).

The vein has been accessed at different elevations by four drifts. The upper three have been previously mapped and sampled while the lowest has been confirmed to a length of 300 m. (975 ft.) with no other examination due to water in the tunnel.

Previous mining and sampling was focused on the quartz vein material. Sampling by Micrex has demonstrated that the altered bedrock next to the Lawson vein also contains gold mineralization. Samples from the hangingwall and footwall alteration zones returned assays of 5.32 g/t over 80 cm, 5.01 g/t over 60 cm, and 2.6 g/t over 30 cm. This would suggest that exploration in and around the Lawson Vein must take into account the potential for extended mineralization beyond the main quartz vein.

Two quartz veins with associated wallrock alteration have also been discovered within a short distance of the Lawson vein. One vein has assayed 4.2 g/t and the other has assayed 5.93 g/t. Alteration associated with the veining assayed 0.980 g/t Au across 1.22 metres.

Alteration is present at both localities and further sampling is required in these areas. These two veins lie within a region previously identified as anomalous by Micrex in 2001 and 2002. Prior results include gold assays as high as 121.16 g/t (3.9 oz.), silver assays as high as 56.9 g/t (1.83 oz), previously reported in the news release of June 26, 2002.

Dean Besserer of Apex Geoscience, who is the Qualified Person on this Project, has reviewed this press release.

Further information may be obtained from Perry Meszaros or S.E. Marshall at (780) 448-0922
or email at mixinfo-1@mixcorp.com

Web site address: www.mixcorp.com

MICREX DEVELOPMENT CORP.

Peace River Diamond Property • Burmis Magnetite/Titanium Property • St. Charles de Bourget Magnetite/Titanium Property • Fort Steel Placer Property • Bighorn Gold Mine • Banks Gold Mine • Mount Royal Gold Mine • Deadwood Gold Mine • Sunburst Gold Property

THE TSX VENTURE EXCHANGE HAS NOT REVIEWED AND DOES NOT ACCEPT RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS RELEASE.

FORWARD LOOKING STATEMENTS

Certain statements in this news release are "forward-looking statements", which reflect management's expectations regarding its property and business operations. All statements other than statements of historical fact contained in this news release are forward-looking statements. Such forward-looking statements involve risks and uncertainties, as they reflect management's current beliefs and are based on information currently available to management. Actual results may differ materially from those anticipated in the statements made. The forward-looking statements are expressly qualified in their entirety by this cautionary statement. The forward-looking statements are made as of the date of this news release and Micrex assumes no obligation to update or revise them to reflect new events or circumstances except as expressly required by applicable securities law. Further information regarding the uncertainties and risks can be found in the disclosure documents filed by Micrex with the securities regulatory authorities, available at www.sedar.com.

Return to Press Release Page