"You've got your mining costs, you've got your inland shipping costs," Mellish said. "There was basically this situation where it's cheaper for them to import coal from Australia, the United States, Indonesia."
Disruptive floods in Australia, the world's biggest exporter of coal, have also led to increased Asian demand for West Virginia coal.
All of these factors have been offset by reductions in domestic coal use. Use of both metallurgical coal, for making steel, and steam coal, for power and electricity, has fallen in recent years.
"The United States is not a major steel producing country like it once was," Muchow said. "Between 2012 and 2016, over 8.5 percent of total coal-fired electric power generation in the United States is being retired, and about 15 percent of the coal-powered electric power generation in West Virginia is scheduled to retire."
Coal power plants are being replaced by natural gas, which produces fewer greenhouse gases, and is inexpensive and abundant.
Mining for natural gas is less labor-intensive and creates fewer jobs than coal mining. Muchow estimates that West Virginia would need a 60 percent increase in natural gas production to offset the jobs lost by a 10 percent decrease in coal production.
"It's likely to go lower," Muchow said of mining employment. "But the decrease we see in 2013 is likely less than it was in 2012."