Hill: Native Americans are pressuring the Obama administration to reject the Keystone XL pipeline, warning the project could infringe on their water rights, harm sacred land and violate Americas treaty obligations. Tribes sent more than 100 pages of letters to the Interior Department earlier this year raising concerns about the project, which would carry oil sands from Canada to refineries on the Gulf Coast. Literally, thousands of sacred and cultural resources that are important to our life-ways and...