Throughout the years, Parker has opposed and protested multiple pipeline projects out of concern for their environmental impact and effects on tribal lands. In September 2016, Parker and other Tulalip tribal members joined Standing Rock in protesting the Dakota Access Pipeline. A month later, on November 15, 2016, Parker joined Eryn Wise, LaDonna Brave Bull Allard, and Judith LeBlanc for the protests' "National Day of Action", during which the four staged a sit-in at the Army Corps of Engineers headquarters and led a crowd of approximately 1,000 protestors around Washington, D.C.