People in power have a history of taking advantage of Native Americans to profit from their land and natural resources, including oil. It is not just the rich and powerful, however. In order for these things to happen, the majority community has to give its approval, even if it is just through its silence.
Today, large energy companies are pushing for crude oil pipeline projects that affect Native peoples, and do so without their consent. The pipelines cross sacred lands, sacred waters, and/or areas where Native peoples have reserved hunting and fishing rights. Two current examples are the Dakota Access Pipeline (DAPL) in North Dakota and Enbridge Line 3, a proposal to expand and reroute a tar sands oil pipeline through northern Minnesota.
Native American peoples are small in number and do not have a strong political voice. Standing up to large companies, powerful interests, and unsympathetic communities is an uphill battle, with an ugly history.