They put a halt to the origanal proposed route for the pipeline because it was determined it would have negative effect on the water source for eight states. Now the Native Americans don't even want the trucks hauling the equipment crossing their land. Its not 100% clear to me if the pipeline will cross the reservation but the Native Americans are saying it will destroy their water supply. Would you be willing to let them put this pipe line across your land?
Here's a link to a Native American news source for more on the story.
Pine Ridge Residents Halt Canadian Mine Equipment Transportation Through Reservation