But for the moment, at least, none of this deters the wildcatters along Wyoming's Powder River.

ECONOMIST: Energy supplies

Other coal companies have drifted out West to the Powder River Basin, where the coal lies right at your feet.

FORBES: Not King Coal

It owns 200 miles of gas pipelines and operates coal-bed methane gas wells in the Powder River Basin of Wyoming.

FORBES: Magazine Article

The lawsuit was filed against the commission by the Powder River Basin Resource Council, Wyoming Outdoor Council, Earthworks and OMB Watch.

NPR: Judge Sides With Wyoming In Fracking Chemical Suit

With demand for Powder River coal growing fast, more tracks are needed.

FORBES: America has coal to last 250 years. Why is there a shortage?

Today, the roughly 443 million tons of coal mined from the Wyoming Powder River Basin is shipped to 34 states, including those in the east.

FORBES: Coal Country Losing Luster

Powder River may account for up to a tenth of that.

ECONOMIST: Energy supplies

This crisis begins, in classic chaos-theory fashion, with a trivial event along the 100-mile railroad track that moves most coal out of the Powder River Basin.

FORBES: America has coal to last 250 years. Why is there a shortage?

Union Pacific was no different but increased coal mining activity in Powder River Basin region situated in parts of Wyoming and Montana could reverse the slide in coal freight volumes for the company.

FORBES: Union Pacific's Coal Freight Business Chugs Ahead After Slowdown

Assign each group one of the following rivers on the top 13 list: Missouri River, Canning River, Eel River, Hudson River, Powder River, Mississippi River, Big Sandy River, Snoqualmie River, Animas River, East Fork Lewis, Paine Run, Hackensack River and Catawba River.

CNN: Rivers feel heat as U.S. energy demand rises