Something historic is happening right now in North Dakota. At the camp in Standing Rock, more than 4,000 indigenous people from 280 tribes have come together, bringing totem poles, handmade canoes, and other sacred objects to commemorate the occasion.

The last time this many tribes gathered to protect their homeland and sacred sites was 140 years ago — in 1876 at the Battle of Little Bighorn, or Custer’s Last Stand, an armed conflict against colonialism.

Now, tribes are uniting in a peaceful, nonviolent collective prayer camp, making pilgrimage to support one of the most important causes of our time: fighting the Dakota Access Pipeline. That includes my own tribe, the Tlingit of Southeastern Alaska, who brought our war canoe. We are standing for our right to water, to keep fossil fuels in the ground, and — importantly — for the value of indigenous lives.