Greencastle Resources Ltd. is an investment company, which engages in the exploration of gold, base metals, oil, and gas. The firm focuses on the collection of royalty interests in Alberta. It operates through the following segments: Investments, Oil and Gas, Mining, and Corporate. The Investments segment comprises of investment in marketable securities and investment in private and public companies. The Oil and Gas segment consists of oil and gas interests. The Mining segment refers to its mining interests in Canada and the U.S. The company was founded by Anthony R. Roodenburg in 1996 and is headquartered in Toronto, Canada.