In CUSHING, Okla. — In energy circles, the town of Cushing is well known as the hub used by New York oil traders to set the benchmark price for all U.S. crude oil. Row after row of giant oil storage tanks are lined up around a moribund downtown and a shopping strip. At the edge of town stands a sign made of white pipes declaring: “Pipeline Crossroads of the World.”

This is also where Trans Canada’s existing Keystone pipeline ends and the southern leg of its new Keystone XL pipeline will begin.

Less well known is the fact that Cushing sits in the Sac and Fox Nation, part of a patchwork of land belonging to Oklahoma’s 38 tribes, each with sovereignty over its own affairs and land.

TransCanada’s plan to dig a trench and bury part of its $7 billion, 1,700-mile Keystone XL pipeline right through this land has unearthed a host of Native American opposition, resentments and ghosts of the past. Winning support in Indian country is one of the last hurdles for the project, which is touted as a key to North American energy security. The question is whether gaining tribal support is a courtesy, as the company puts it, or a legal obligation.

Under Chief Black Hawk, the Sac and Fox tribe, originally from the Great Lakes region, fought bloody skirmishes in the 1800s against other tribes and federal troops. Ultimately, the tribe signed a series of treaties that pushed it to Illinois, then Iowa, then Kansas and finally in the 1870s to the Indian Territory — now known as Oklahoma.

Along the way, many of its members died of smallpox and other hardships.

George Thurman, chairman of the Sac and Fox Nation and a descendent of Black Hawk, is worried that the pipeline could dig up unmarked graves or other sacred archaeological sites even on private lands.

“There are mass graves where people were buried after dying of smallpox,” Thurman said over lunch at Rudolpho’s Mexican Restaurant in a strip mall on Cushing’s East Main Street. “There could be another buried out there.”

His aide for cultural and historic preservation, Sandra Massey, added: “How many times do we have to move? Our dead are never at rest.”

Nothing is clear-cut about the web of laws regarding Native Americans.

“There is no legal obligation to work with the tribes,” said Lou Thompson, TransCanada’s top liaison with Native Americans. “We do it because we have a policy. We believe it’s a good, neighborly thing to do.” He said the pipeline “is not passing through any tribal lands.”

But many Native Americans in the United States — and their lawyers — insist that there are legal obligations under 19th-century treaties that affirmed sovereign status of Native American tribes, which do not pay state or federal taxes and which have their own governing councils and police forces.

Moreover, the more recent National Historic Preservation Act and the Native American Graves Protection and Repatriation Act of 1990 both provide for the protection of Indian burial sites and artifacts. “When it comes to jurisdiction, it’s a tough question to answer,” said Jennifer Baker, a Colorado-based lawyer who has worked closely with South Dakota tribes. “History has developed so that legal truths get overshadowed by factual realities, and judges tend to mold the law to reflect factual realities.”

Meeting with tribal leaders

A key reality is this: Even after Trans-Canada has secured the right to build from federal and state officials, it still could run into a hitch on — or near — tribal land.

TransCanada is trying to hammer out issues with Oklahoma and Texas tribes without a fight, so it can get on with digging. The company met with tribal leaders on July 11 at the Caddo Nation headquarters in Binger, Okla., and again on Aug. 3 at the Choctaw Inn, a hotel in Durant near the Choctaw tribe’s headquarters and one of its seven casinos. Another meeting is set for Tulsa.

TransCanada has flown some tribal leaders to Calgary to tour the company’s operations center where banks of computers monitor thousands of points along existing pipelines. And it has trained members of the Alabama Coushatta tribe from south Texas to act as monitors during construction in case Indian remains or artifacts turn up on the tribe’s stretch of the pipeline.

“We walk the entire pipeline route and identify sites and alter the route of our pipeline to avoid those sites,” said Thompson of TransCanada.

He said that the company has also asked the tribes to conduct their own studies of sensitive sites. “Sometimes there are areas very significant to the tribes that don’t bear any physical evidence,” Thompson said. “It might be used to hold ceremonies, but if you walked there you wouldn’t see any evidence.”

Thompson’s efforts have new impetus. In July, TransCanada received the permits it needs to build the Keystone XL’s southern leg, which will run from Cushing to Port Arthur, Tex., and the company already has started work.

Yet some of the Native Americans who attended the meetings believe the company is moving too fast. Massey said, “They need to learn whose land is where.” Moreover, she added, monitors from one tribe won’t know the traditions and desires of other tribes.

While Thompson said tribes have looked at programs for construction work, Massey said the plans still lack input from many tribal leaders. “It seems like TransCanada really wants to work with us,” she said dryly. “We’ll see.”

Massey also worries about leaks. In the 1960s, saltwater flooding resulting from Tenneco’s failure to properly plug abandoned wells contaminated Sac and Fox drinking water and destroyed land and pecan groves. Three federal agencies joined the tribe in a lawsuit and the pipeline company El Paso (which bought Tenneco) agreed in 1997 to dig wells, provide potable water and plant trees. The wells still provide water to the tribe.

In other states, TransCanada’s route for the Keystone XL pipeline neatly avoids Native American lands.

In South Dakota, TransCanada threaded its way in between the seven major reservations that cover about 16 percent of the state. The Keystone XL would enter the northwest corner of South Dakota from Montana then move diagonally. It would run southwest of the Cheyenne River Sioux Indian Reservation and north of the Pine Ridge Reservation of the Oglala Lakota. It would narrowly miss the Rosebud Indian Reservation, and travel south of the Crow Creek and Lower Brule.

“It’s not necessarily by design,” Russ Girling, TransCanada’s chief executive, said in an interview. “When you build a pipeline . . . the least environmental disturbance is a straight line from A to B.”

In Oklahoma, however, where the U.S. government drove tribes from the East Coast and all over the Western frontier, it is difficult to sidestep Indian burial or archaeological sites or to circumvent the patchwork jurisdiction of tribal governments. More than a century ago, the federal government broke up tribal lands into allotments, which Indian individuals could later sell. The goal was to shrink tribal areas, make way for a land rush by whites and prepare for Oklahoma statehood.

TransCanada has sought to stick to privately owned plots. But a wide layer of sovereign tribal authority remains and burial sites could exist on land no longer owned by tribal members.

Near the giant oil tank farms of Cushing lies a cemetery that holds the family of legendary Olympian Jim Thorpe, a Sac and Fox member whose remains the tribe is trying to repatriate from Pennsylvania. About 20 minutes down the road, Iowa tribal chairman Janice Rowe-Kurak bows her head and folds her hands as she pays her respects before a small cemetery hidden behind trees at a cousin’s ramshackle house.

Many tribal leaders in Oklahoma, including Kurak, have no objection to Trans Canada’s pipeline plan.

TransCanada says that there will be three monitors and one tribal liaison on every segment of pipeline under construction. “There’s always the possibility that we are confronted with an unanticipated discovery that requires mitigation,” Thompson said. “Our tribal monitors’ main responsibility is to help us identify those unanticipated discoveries. They are rare, but they do occur.”

But other tribal leaders remain troubled, despite TransCanada’s assurances.

“All we know is that it’s coming through our tribal jurisdiction,” Thurman said. “They say they will stop digging if they hit something, but there is no guarantee that they are going to stop.”

If they don’t stop, the tribes could go to federal court or ask the Interior Department’s Bureau of Indian Affairs to intervene.

After the Oklahoma tribal leaders’ first meeting with Thompson, Massey sat on the edge of the annual Sac and Fox powwow, part ceremony and part country fair featuring jumbo corn dogs, frozen chocolate-dipped cheesecake and fish tacos. Men in feathered regalia and women in long patterned skirts and necklaces danced in a circle around a dozen traditional drummers. Others watched from folding chairs and bleachers as an announcer over a microphone urged people to participate.

“Some things are sensitive to us. If they want to go through a grave, the ground around it may be sacred, too,” Massey said, shaking her head. “We’re all wary. We don’t trust anybody.”

‘Sacred site’

Other tribes are also worried about the pipeline excavation. In February, Robert Cast, the historic-preservation officer of the Caddo Nation of Oklahoma, with homelands in four states, wrote to the federalAdvisory Council on Historic Preservation warning of “imminent and irreparable damage” to an archeological site in Lamar County, Tex.

It said that the “sacred site,” which was first excavated by archaeologists in 1931, “contains burials and specific artifacts of ceremonial use along with iconographic images on artifacts that are of utmost importance to the history of the Caddo people.”

TransCanada’s Thompson said that the pipeline route in that location has been moved and that the Caddo council approved a resolution supporting the project. Cast, who is still marking up pipeline maps so that TransCanada can avoid sensitive areas, said “it’s not so much that we’re in support of the pipeline, but we’re in support of working together to make sure our interests are looked after.”

The route has inadvertent historical echoes, too. From northern Nebraska through Kansas, it is almost identical to what is known as the trail of tears for the Ponca Tribe. The Poncas, who in the 19th century did almost everything the federal government asked including attending church and farming, were still forced to move to Oklahoma.

A history of broken promises, and treaties, has fueled opposition, especially in South Dakota. Last October, a group of Indians were ejected from a speech by President Obama after shouting that the president should respect the tribes and stop the pipeline. On Feb. 18, the Black Hills Sioux Nation Treaty Council demanded that Obama and Congress prevent construction of the Keystone pipeline

“The Great Sioux Nation hereby directs President Barack Obama and the United States Congress to honor the promises of the United States made through the 1851 and 1868 Fort Laramie treaties by prohibiting the proposed Keystone XL Pipeline and any future projects from entering and destroying our land without our consent,” said a resolution approved by all seven delegations.

The Fort Laramie treaties ceded all of South Dakota west of the Missouri River to the Lakota tribes, or Sioux. While legislation has reduced the size of that reservation, the treaties were never revoked. Baker, the lawyer, says they should still be considered in force.

Moreover, while the pipeline doesn’t cross current reservation boundaries in South Dakota, it runs across rivers and water pipelines that do.

Even under congressional legislation, a process of consultation is required for all federal agencies. But Cast said that the State Department, which is weighing the Keystone XL cross-border permit, told tribes to voice concerns at open meetings with other citizens.

“The State Department has its own process talking about government-to-government talks and the sovereignty of tribes, but they don’t really believe that,” Cast said. “Our main issues are with the federal agencies. I think they abandoned the tribes.”

Baker said: “The consultation process is really broken. Tribal interests are rarely able to be brought forward properly, and when they are they are rarely listened to.”

Mineral rights

Native Americans have had success melding their interests with business and oil development. The Sac and Fox, like many other tribes, rely heavily on casinos for income. The tribe said in a May newsletter that it received two-thirds of its revenue from its casinos.

The oil and gas industry is a familiar presence, too. Though Oklahoma was chosen as Indian Territory in part because it was thought to be worth little, the state turned out to hold substantial oil and natural gas reserves. That led to further reductions in Indian land holdings while derricks and small boomtowns sprung up. Throughout Indian areas today, old pipelines, some dating to the 1930s, can be seen alongside gently seesawing pump jacks, and the old boomtowns remain largely deserted.

The Bureau of Indian Affairs in the Interior Department has acted as Indians’ trustee for these resources, though Native Americans have complained that it has often done a poor job of guarding their interests. The Osage tribe, which in 1906 was savvy enough to retain mineral rights when private allotments were carved out in Osage County, filed a lawsuit against the Interior Department for mismanaging those mineral rights; last October, the government settled for $380 million.

When it comes to the Keystone XL pipeline, observers say there is an element of tribal politics in the opposition. During the 2008 campaign, the Crow received attention for making Obama an honorary member, bestowing him with the name “One Who Helps People Throughout the Land.”

Now, some believe that Sac and Fox leader Thurman feels slighted by Obama, who initially failed to invite him to the March speech the president delivered in Cushing. This was a special affront because Cushing is part of the Sac and Fox Nation. At that event, Obama announced his support for the southern portion of the Keystone XL pipeline.

Thurman only heard about the visit from Kurak, who is a friend. Kurak had been invited because she caught Obama’s attention at a meeting in Washington.

Kurak, the Iowa Nation chairman, sympathizes with Thurman. She said, “All we’re asking for is respect, respect for us as a people.”

Baker, the lawyer, who comes from Oklahoma, stresses that opposition is rooted in Native American belief.

“Above all the land is sacred,” she said. “It’s not just a mantra. People really do see this as sacred land. It really causes a lot of people a lot of pain, particularly the elders. They recognize the damage this has the potential for.”