Other Non-Mining Operations:
In addition to our mining operations, we operate several subsidiaries which provide auxiliary services for our coal mining operations. Rhino Trucking provides southeastern Ohio coal operations with reliable transportation to our customers where rail is not available. Rhino Services is responsible for mine-related construction, site and roadway maintenance and post-mining reclamation. Through Rhino Services, we plan and monitor each phase of our mining projects as well as the post-mining reclamation efforts. We also perform the majority of our drilling and blasting activities at our company-operated surface mines in-house rather than contracting to a third party.
Other Natural Resource Assets:
Oil and Gas
In addition to our coal operations, we have historically invested in oil and gas mineral rights that have generated prior revenues for us, which helped to diversify our income streams. We have also expanded our business to include infrastructure support services for oil and gas operators, primarily in the Utica Shale region.
In September 2014, we made an initial investment of approximately $5.0 million in a new joint venture, Sturgeon Acquisitions LLC ("Sturgeon"), with affiliates of Wexford Capital and Gulfport Energy. Sturgeon subsequently acquired 100% of the outstanding equity interests of certain limited liability companies located in Wisconsin that provide frac sand for oil and natural gas drillers in the U.S.
In November 2014, we contributed our investment interest in a joint venture, Muskie Proppant LLC (“Muskie”) with affiliates of Wexford Capital that was formed to provide sand for fracking operations to drillers in the Utica Shale Region and other oil and natural gas basins in the United States to Mammoth Energy Partners LP (“Mammoth”) in return for a limited partner interest in Mammoth. Mammoth was formed to provide services to companies, which engage in the exploration and development of North American onshore unconventional oil and natural gas reserves. Mammoth provides services that include completion and production services, contract land and directional drilling services and remote accommodation services. The non-cash transaction was a contribution of our investment interest in the Muskie entity for an investment interest in Mammoth. Thus, we determined that the non-cash exchange of our ownership interest in Muskie did not result in any gain or loss. As of December 31, 2015, we recorded our investment in Mammoth of $1.9 million as a long-term asset, which we recorded as a cost method investment based upon our ownership percentage. In October 2016, we contributed our limited partner interests in Mammoth to Mammoth Energy Services, Inc. (“Mammoth Inc.”) in exchange for 234,300 shares of common stock of Mammoth Inc. The common stock of Mammoth Inc. began trading on the NASDAQ Global Select Market in October 2016 under the ticker symbol TUSK and we sold 1,953 shares during the initial public offering of Mammoth Inc. and received proceeds of approximately $27,000. Our remaining shares of Mammoth Inc. are subject to a 180 day lock-up period from the date of Mammoth Inc.’s initial public offering.
Timber Wolf Terminals
In March 2012, we made an initial investment of approximately $0.1 million in a new joint venture, Timber Wolf Terminals LLC ("Timber Wolf"), with affiliates of Wexford Capital. Timber Wolf was formed to construct and operate a condensate river terminal that will provide barge trans-loading services for parties conducting activities in the Utica Shale region. The initial investment was our proportionate minority ownership share to purchase land for the construction site of the condensate river terminal. Timber Wolf has had no operating activities since its inception.
Incidental to our coal mining process, we mine limestone from reserves located at our Sands Hill mining complex and sell it as aggregate to various construction companies and road builders that are located in close proximity to the mining complex when market conditions are favorable. We believe that our production of limestone provides us with an additional source of revenues at low incremental capital cost.