Energy companies are rushing to develop unconventional sources of oil and gas trapped in carbon-rich shales and sands throughout the western United States and Canada. So far, government officials have shown little concern for the environmental consequences of this new fossil-fuel development boom.

The most direct path to America’s newest big oil and gas fields is U.S. Highway 12, two lanes of blacktop that unfold from Grays Harbor in Washington State and head east across the top of the country to Detroit.

The 2,500-mile route has quickly become an essential supply line for the energy industry. With astonishing speed, U.S. oil companies, Canadian pipeline builders, and investors from all over the globe are spending huge sums in an economically promising and ecologically risky race to open the next era of hydrocarbon development. As domestic U.S. pools of conventional oil and gas dwindle, energy companies are increasingly turning to “unconventional” fossil fuel reserves contained in the carbon rich-sands and deep shales of Canada, the Great Plains, and the Rocky Mountain West.