On Monday the company said capacity would increase by 40% annually to 4.5 million tons over the next few years.
The growth plan also includes advancing operations north of the existing site underground. Given favorable market conditions, Gateway can access an additional 280Mt of reserves.
"We are expanding Gateway to serve one of the fastest-growing markets in the United States," Peabody chairman Gregory Boyce said.
"[The mine] has earned a reputation as one of the safest and most productive operations in the Midwest. This expansion demonstrates the strength of our leading reserve base to capitalize on long-term growth opportunities in high-demand, low-cost regions."
While the extension is subject to permitting and regulatory approvals, the producer said progress is being made with regards to licensing and mine engineering activities.
Gateway, located near Coulterville in southern Illinois, is just one project on Peabody’s radar for strategic global growth; the company is expanding six of its Australian operations to serve the increase in demand from Asia.
Additionally, ramp-up efforts are continuing at Peabody’s Bear Run mine in Indiana and production increases are ongoing at the El Segundo complex in New Mexico.
The 200-worker, 3.2Mtpa Gateway operation has earned several state and national safety, sustainability and good neighbor honors, including the 2009 Illinois Mining Institute Awards of Excellence for being the state’s safest mine.