From prairie to the White House - Inside a Tribe's quest to stop a pipeline

By Ernest Scheyder and Valerie Volcovici CANNON BALL, N.D./WASHINGTON (Reuters) - Three days after guard dogs attacked Native Americans protesting an oil pipeline project in North Dakota in early September, an unprecedented event took place at the White House. Brian Cladoosby, president of the National Congress of American Indians, which represents more than 500 tribes, spoke to nearly a dozen of President Barack Obama's Cabinet-level advisers at a September 6 meeting of the White House's three-