Triangle Petroleum Corporation is an energy holding company. The Company has three principal lines of business: oil and natural gas exploration, development, and production; oilfield services, and midstream services. It conducts these activities in the Williston Basin of North Dakota and Montana through the Company's two principal wholly owned subsidiaries and its equity joint venture. Triangle USA Petroleum Corporation (TUSA) conducts its exploration and production operations by acquiring and developing unconventional shale oil and natural gas resources. RockPile Energy Services, LLC (RockPile) is a provider of hydraulic pressure pumping and complementary services. Caliber Midstream Partners, L.P. (Caliber) is its 28.3%-owned joint venture with First Reserve Energy Infrastructure Fund (FREIF). Caliber provides crude oil, natural gas and fresh and produced water gathering, processing, and transportation services.