Western Bituminous

Castle Valley Mining Complex:

In August 2010, we completed the acquisition of certain mining assets of C.W. Mining Company. The assets acquired are located in Emery and Carbon Counties, Utah and include coal reserves and non-reserve coal deposits, underground mining equipment and infrastructure, an overland belt conveyor system, a loading facility and support facilities. For the year ended December 31, 2014, we produced approximately 1.1 million tons of steam coal from this complex. As of December 31, 2014, the Castle Valley mining complex included an estimated 21.5 million tons of proven and probable coal reserves.

McClane Canyon Mining Complex:

The McClane Canyon mine is located near Loma, Colorado and is on property leased from Bureau of Land Management. As of December 31, 2014, the McClane Canyon complex included an estimated 6.3 million tons of proven and probable coal reserves. As of December 31, 2013, we made a strategic decision to permanently close the mining operations at our McClane Canyon mine, which had been idle since the end of 2010.