TORONTO, ONTARIO--(CCNMatthews - Aug. 17, 2006) - Greencastle Resources Ltd (TSX VENTURE:VGN) is pleased to announce that exploration is in progress on Greencastle's 100% owned Coal Canyon property. A program of two core holes, each to an approximate depth of 1,300 feet, is designed to test a zone in the Grouse Creek Fault. Earlier work identified anomalous gold values within a zone of hydrothermally altered sedimentary rocks, thought to be Lower Plate rocks below the Roberts Mountain Thrust. The Grouse Creek Fault trends under pediment cover to the northwest, where Barrick's ET Blue project is located, approximately 10 km to the north towards the Cortez Hills area.

Greencastle geologists have completed compiling and assimilating recently acquired data relating to the Company's Jewel Ridge project. A reverse circulation drill program is planned to evaluate a number of targets later this summer. Jewel Ridge is located between the former Ruby Hill gold mine and the Lookout Mountain gold deposit, currently under exploration by Staccato Gold Resources Ltd. In 2004, Greencastle reported hole HRC-11, which returned 2.1 grams per tonne (g/t) Au over 39.6 metres from 94.5 m to 134.1 m, including 2.7 g/t Au over 19.8 m from 94.5 m to 114.3 m. Jewel Ridge is located approximately five kilometres south of the former Ruby Hill gold mine, which was operated by Homestake Mining Co. from 1997 until 2002, producing approximately 135,000 ounces of gold annually and currently being prepared for additional production by Barrick Gold Corp.

In addition to two large gold exploration concessions in Niger, West Africa, currently under option to Orezone Resources Inc., Greencastle is advancing four gold exploration projects, located on the Battle Mountain-Eureka mineral trend, Nevada. This highly productive regional trend hosts multi-million ounce gold deposits such as Barrick's Pipeline deposit and recent discovery nearby at Cortez Hills.

In Saskatchewan, development continues at the Primate oil project where Greencastle holds a gross overriding royalty. Production at Primate continues to increase with three new wells completed during June and July. Royalty income for the second quarter ended June 30 was $519,856. Second quarter profit increased to $367,864. Profit year to date was $437,476.

This news release includes certain "forward looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995. Without limitation, statements regarding potential mineralization and resources, exploration results, and future plans and objectives of the Company are forward looking statements that involve various degrees of risk. The following are important factors that could cause the Company's actual results to differ materially from those expressed or implied by such forward looking statements: changes in the world wide price of commodities, general market conditions, risks inherent in exploration, risks associated with development, construction and mining operations, the uncertainty of future profitability and the uncertainty of access to additional capital. The Company relies on litigation protection for forward looking statements.

Issued and Outstanding: 35,882,005

FOR FURTHER INFORMATION PLEASE CONTACT:

Greencastle Resources Ltd.
Anthony Roodenburg
CEO
(416) 485 1327
www.greencastleresources.com