Greencastle Resources Ltd. engages in the exploration and development of gold, base metal, oil and gas properties, and royalties. The company operates through Investments in Private and Public Companies; Oil and Gas Interests; and Mining Interests segments. It holds interests in two oil and gas properties, which include Primate and Primate North projects located in Saskatchewan, as well as the Ferrier project located in Alberta, Canada. The company also holds interests in the Jewel Ridge project and the Indian Creek project located in Nevada; and the Mayflower property consists of 64 claims located in the northwestern Ontario. In addition, it has an option agreement to earn 100% interest in the Seagrave property consists of 131 claim units located in the Birch-Uchi Greenstone Belt, Red Lake Mining Division in northwestern Ontario. Greencastle Resources Ltd. was founded in 1996 and is headquartered in Toronto, Canada.