The new operation is projected to reach full production levels by August with a staff of 35. JRL officials did not disclose details of the expansion.

"As our company continues to evolve, we will increase our reliance in our underground mining operations to meet the demand for our coal," CEO Tim Lusby said. "We believe that our underground mining offers a consistent and cost-effective method of extracting coal."

JRL Energy, established in October 2016 to mine metallurgical and thermal-grade coal in south-east Kentucky, has leased both surface and underground mining interests.