In mid-September this year, as sharp winds howled across the Great Plains, indigenous leaders from either side of the U.S.-Canada border held an "emergency meeting" in the basement of a South Dakota casino. They came from all over -- one flew in from Canada's frigid Great Bear Lake near the Arctic Circle, a husband and wife drove east on Highway 18 from their reservation, and several more drove west, on Interstate Highway 90.

The casino itself (official slogan: A little bit of Vegas on the prairie) is not much to look at. The low building sits by itself on the prairie near the southern edge of the Rosebud Indian Reservation, almost straddling the border between Nebraska and South Dakota. For two days, the indigenous delegates -- men and women, mostly middle-aged and older -- huddled downstairs, drinking coffee out of Styrofoam cups, and nibbling on salted peanuts and M&M candies.

How to radically alter the energy policy of the United States, they wondered, and keep a foreign company far away from their land? They prayed to their ancestors for guidance. They took smoke breaks under an enormous grey sky.

After two days, they drafted a Mother Earth accord that they hope will galvanize indigenous opposition to the most contentious infrastructure proposal in North America: a privately-built, 1,661-mile-long oil pipeline set to carry crude from Alberta's oil sands to refineries on the Texas Gulf Coast. Some say they're fighting for the safety of their peoples -- and others, to redress generations of conflict, poverty, and injustice. "Our ancestors protected the land when they were alive," Rosebud Tribal Chief John Spotted Tail said at the meeting. "Our belief is that we need to do the same."

Great Plains country

From the air, South Dakota resembles a tile floor where earthy rectangles of green, brown, yellow and red line up with geometric precision. The view from the ground reinforces that image, adding texture, sound and smell. Highways run to distant points on the horizon. Fields of corn, wheat, soybeans and sunflowers ripple in the wind. The odour of manure drifts across the land, sometimes wafting even to Sioux Falls, the state's largest city.

Driving down the interstate highway, you can tune to KBHB 810 AM Five State Ranch Radio near Rapid City, catch the daily Farm and Ranch Review on KWYR Country 1260, or listen to KILI Radio 90.1, Voice of the Lakota Nation.

Scattered among the farmer-settlers, South Dakota has one of the largest indigenous populations in the U.S., with more than 71,000 Lakota, Dakota, and Nakota peoples (Sioux, as they are known by outsiders) spread across eight reservations and beyond. Theirs is often a marginalized existence, separated by history and culture, as well as poor health and poverty, from the agricultural mainstream that surrounds them.

But local leaders are hoping to wield outside influence in coming weeks over one of the most important environmental decisions in Barack Obama's presidency: whether or not to approve TransCanada's Keystone XL Pipeline.

Keystone XL is the Calgary-based energy company's most important project. Canadian analysts expect it to add C$500 million to C$700 million to its balance sheets each year. Those earnings hinge on Obama's acceptance of the argument -- promoted by Alberta's oil sands industry and its political supporters -- that pumping an extra 500,000 barrels of oil each day from friendly Canada will help wean the U.S. off Middle Eastern oil.

A fierce opposition, including Democratic party members of the U.S. Congress, environmental activists and local ranchers, has delayed the proposal for years, framing it as a mortal danger to the planet's climate and to the rivers and aquifers of the “American heartland.” For some indigenous peoples on South Dakota's Great Plains, the controversy has an added, historical, significance. They see TransCanada as the latest in a long line of unwanted intruders on their ancestral homeland.

'Something bad is coming to our nation'

"Excuse me if I just spoke too fast for you to understand," Alex White Plume said, moments after delivering an opening prayer in the Lakota language. His quick laughter softened the joke at the expense of the white English speakers in the casino basement. The 59-year-old White Plume and his wife, Debra, were among the first to arrive at the "emergency meeting" of indigenous leaders at the Rosebud Tribal Casino. They sat at the right arm of a U-shaped table configuration, notebooks open.

The meeting had been organized only the week before, and opening attendance was modest. Down the short end of the "U" to their left were several local farmers, dressed in flannel shirts and blue jeans. Nearby were representatives from the Rosebud Tribal council and on the other side was an anti-pipeline activist from Nebraska. Enclosed in the center, facing a large projector screen, was Marty Cobenais, the pipeline campaigner of the Indigenous Environmental Network and one of the meeting's organizers. An aerial shot of an oil sands operation in northern Alberta filled the projector screen: miles of strip-mined blackness where thick woodland used to be. "Jesus," muttered one of the farmers. White Plume remarked: "Something bad is coming to our nation and to our land."

The future of oil?

Whatever your view of Alberta's oil sands industry, there's no denying its sheer visual spectacle. Picture the boreal forest, like a great green blanket spread across northern Canada. Now picture a gash in the fabric that reveals 426 square miles of toxic lakes and bare, black earth, where shovels and trucks the size of small buildings mine "bitumen," a thick mixture of sand, clay and oil. (A tiny patch measuring 0.64 square miles has been certified by the provincial government as reclaimed.) At the edges of this rip, the green blanket appears to fray, cut through with production wells, pipelines, access roads, and processing facilities -- essential elements of the system of high-pressure steam injections that let producers access deeper deposits. Each year, this frenzy of industrial activity pumps out close to 40 megatonnes of greenhouse gases, more than all the cars on Canadian roads.

Much of the bitumen produced here is diluted with a chemical cocktail of industrial solvents -- including benzene, a known carcinogen -- and then sent via pipeline to the U.S. Midwest. So much of this "dilbit" is shipped south, in fact, that Canada has become the number-one supplier of crude oil to the U.S., shipping one million more barrels each day than Saudi Arabia.

And this output is only the beginning. The Canadian Association of Petroleum Producers expects production to more than double in the next 14 years. But for that to happen, the C$100 billion industry needs a way to get that oil to foreign markets. It needs pipelines. "If there was something that kept me up at night," Alberta Energy Minister Ron Liepert told the Globe and Mail this summer, "it would be the fear that before too long we're going to be landlocked in bitumen. We're not going to be an energy superpower if we can't get the oil out of Alberta.”

Pipeline politics

Climate change activists hoped to keep Liepert sleepless in late August, when they began staging a massive protest against TransCanada's Keystone XL. Each day for two weeks, people from across the continent stood, sat, and chanted in an off-limits area in front of the White House in Washington, D.C. More than 1,250 activists, including actress Daryl Hannah, writer Naomi Klein and environmental leader Bill McKibben were led away in handcuffs. (After some time in a detention center and payment of a $100 fine, all the detainees were freed.)