Governor Matt Mead confirmed that sometime this month Wyoming mines will produce their 10 billionth ton of coal.
"10 billion is an awful lot. I have a hard time with the number of zeros," said Gillette Mayor Tom Murphy.
That number is hard to put in perspective. But the milestone shows the country's dependence on Powder River Basin coal.
"40 percent of the nation's electricity comes from coal-fired power plants and this county produces half that amount of coal," said Murphy.
"We pride ourselves on being the Energy Capitol of the World," said Jack Clary, manager of mining operations for Wyodak Resources.
The Wyodak Mine's contribution to Wyoming's 10 billion tons comes to four million a year, which supplies six power plants with energy.
"Provides electricity to South Dakota, all of Wyoming, and some in Colorado," said Clary.
There is still a lot of coal in the ground and that means some people are already looking ahead to the state's 20 billionth ton.
"Our current reserves will carry us up to 2055," said Clary.
"I also am reminded that we have maybe close to 550 billion tons. So it's a drop in the bucket when you look at what reserves we have," said Murphy.
A state coal geologist reviewed historical records dating back to 1865 and current production data to determine when Wyoming might reach that 10 billion milestone.