At sundown, Montgomery Brown meets me by the information tent. He has a paper plate piled with brownies in one hand and a toothbrush in the other. The 25-year-old youth organizer and Navy-trained combat medic from the Standing Rock Sioux tribe has been up since daybreak.

Brown and I walk past hand-painted “NO MEDIA” signs. We wander through a kitchen, where volunteers are chopping vegetables and boiling pots of soup over an open fire, past kids chasing each other in a game of tag. Clusters of towering white teepees and neon, synthetic tents hug the ground. They are grouped into small encampments for a half mile in every direction, around central fires that burn day and night and send plumes of smoke into the sky.

“Every time I walk around this camp,” Brown says, “… I hear those kids laughing and playing — it just reaffirms that I’m not just fighting for myself or my family. I’m fighting for everybody.”