Abstract: On August 31, 2006, Employee #1 was working as a trouble shouter near Wilsall, MT, for a geophysical services company that discovered oil and gas reservoirs. The employee was driving an ATV, while wearing a helmet, on moderately steep terrain when he lost control of the vehicle and suffered an accident. Among the potential causes of the accident were speeding and excessive loading of the front end of the vehicle, as it was loaded over the 65 lbs recommended by the manufacturer. A coworker found the employee lying lifeless on the ground with the rear portion of the ATV resting on his neck. The coroner concluded that the cause of death was mechanical asphyxiation.