Give two reasons the Sioux were angry and worried about their future?​

In 2016, a large Texas-based energy transfer partners company initiated construction on the Dakota Access Pipeline, reaching near the Standing Rock Reservation, which spans parts of both North and South Dakota. The Sioux expressed anger and fear that the extensive oil extraction would harm nature, pollute the Missouri River, and destroy sacred Native American sites. They are particularly concerned that this construction poses a direct risk to their ancient burial grounds and culturally significant locations, which represent the last sanctuaries of the tribe. Subsequent to this, descendants of the Sioux started public campaigns to halt the construction, and while an environmental impact assessment was launched under Obama, it was ultimately concluded by President Trump who approved the project. North and South Dakota are in the Midwest of the US, named after the Sioux tribe, extending from the Rocky Mountains to the Mississippi River. In Sioux, 'Dakota' means allies or friends. Both Dakotas are bisected by the Missouri River, a major tributary of the Mississippi, with a population of 750,000 in the North and an additional 100,000 in the South, each state accounting for 15 Native American reservations.