Protests against the DAPL and Keystone XL pipelines, which began in 2014, continued in 2017.
The Trump administration officially approved both pipelines this year. The DAPL started delivering oil in May, and the Keystone pipeline extension's construction was greenlit in November.
Opponents to the pipelines argued that each one will lead to more CO2 being emitted, and harm local wildlife, farmland, and water sources.
In early November, the existing Keystone pipeline spilled over 200,000 gallons of oil.