As aging coal-fired power plants are shut — roughly 20 of 380 have closed or are in the process of shutting since Mr. Trump took office — coal’s share of the nation’s power mix has plummeted from nearly half in 2008 to roughly a third today.

Last year, coal consumption in the United States fell by 2.4 percent, falling to its lowest level in nearly four decades. In the early weeks of 2018, national coal production has continued to decline from a year ago despite the frigid winter. A weather-related increase in exports last year yielded a modest gain in jobs, but it is not considered sustainable.

The decline in demand has forced a 38 percent drop in the nation’s coal production in a little less than a decade. Now only the most efficient mines containing the highest-quality coal are able to survive.

The 4 West mine, like many that produce coal for power utilities in Appalachia, is expensive to run. Its coal seam is thin and of lower quality than competing mines, and its traditional form of mining requires costly methods to stabilize roofs to protect against the kind of accidents that caused the deaths of two miners at 4 West over the last three years. Government fines and management turmoil also took their toll.