The Sand Hills of Nebraska are a unique Great Plains prairie ecosystem. The rolling dunes, rising to 300 feet, cover about a quarter of the state, and because the grasses and wildflowers there are adapted to wet, sandy soil, many grow nowhere else. Thousands of ponds and lakes dot the Sand Hills, nourishing the Ogallala Aquifer.

This region is an unlikely ground zero for a growing rebellion against a different kind of sand — the Athabascan oil sands of Alberta, 1,400 miles to the north. But that is precisely what is happening as energy companies seek to construct a pipeline from Alberta’s tar sands — the second-largest petroleum deposit in the world, after Saudi Arabia — across the length of the U.S. to refineries in Texas, passing through the Sand Hills on its way.

And the so-called Keystone XL pipeline is not the only tentacle of the tar sands poised to spread across North America: Energy companies are seeking to build a second pipeline to carry tar sands oil across the wild heart of British Columbia, while other firms are proposing to truck gargantuan equipment for the tar sands project along narrow roads in one of most remote parts of the northern Rocky Mountains.

Environmentalists, farmers, ranchers, elected officials, native people, and a host of others have risen up in opposition to the potential environmental threats posed by the expanding reach of Alberta’s tar sands. Some opponents are concerned that pipelines or oversized equipment running through their communities pose an unacceptable environmental risk. But for others, the battle is about something far larger. They believe that wreaking so much environmental destruction to continue expanding supplies of planet-warming fossil fuels is fundamentally wrong, noting that the tar sands project has razed hundreds of square miles of boreal forest, led to the creation of dozens of toxic tailings ponds, and released vast quantities of CO2. And they are convinced that choking off the tar sands pipelines is a way of stopping, or at least hampering, the development of the Alberta tar sands themselves.