Dawson Geophysical Company, formerly TGC Industries, Inc., along with its wholly owned subsidiary, Eagle Canada, Inc. (Eagle Canada), is a provider of seismic data acquisition services throughout the continental United States and Canada. The Company is engaged in the geophysical service business of conducting two dimensional (2-D) and three dimensional (3-D) surveys for clients in the oil and gas business. As of December 31, 2013, it operated 8 seismic crews, five in the United States and three in Canada. These seismic crews supply seismic data primarily to companies engaged in the exploration and development of oil and natural gas on land and in land-to-water transition areas. As of December 31, 2013, the Company owned equipment for 16 land-based seismic data acquisition crews and 73 vibration vehicles. Each crew consists of approximately 40 to 80 technicians with associated vehicles, geophones, a seismic recording system, energy sources, cables, and a variety of other equipment.