Winter weather at Dakota Access pipeline protests

Travelers arrive at the Oceti Sakowin camp and enter a tent flying an upside-down American flag near Cannon Ball, N.D., on Dec. 2, 2016.

People stand outside a dome used as a community center and sleeping area at the Oceti Sakowin camp where people have gathered to protest the Dakota Access oil pipeline in Cannon Ball, N.D., Friday, Dec. 2, 2016.

A woman watches the sunset at the Oceti Sakowin camp where people have gathered to protest the Dakota Access oil pipeline in Cannon Ball, N.D., Friday, Dec. 2, 2016. Hundreds of protesters fighting the Dakota Access pipeline have shrugged off the heavy snow, icy winds and frigid temperatures that have swirled around their large encampment.

Night falls on the Oceti Sakowin camp on the edge of the Standing Rock Sioux Reservation outside Cannon Ball, N.D., on Dec. 1, 2016.

Blackhorse Shasta, of Oregon, chops wood on at the Oceti Sakowin camp near Cannon Ball, N.D., on Nov. 30, 2016. Camp dwellers are getting ready for the hardships of a long stay. Mountains of donated food and water are being stockpiled, as well as firewood, much of which has come from outside of North Dakota, the least-forested state in the nation.

An activist climbs a hill to sled near the Oceti Sakowin camp on the edge of the Standing Rock Sioux Reservation outside Cannon Ball, N.D., on Dec. 1, 2016.

Corn covered in snow hangs outside a tent at the Oceti Sakowin camp near Cannon Ball, N.D., on Nov. 29, 2016.

A person prays along the Cannonball River during a Native American water ceremony at the Oceti Sakowin camp near Cannon Ball, N.D., on Nov. 29, 2016.

Army veteran James White, a member of the Lakota Native American tribe, makes a snow angel on a closed bridge during a protest across from police protecting the Dakota Access oil pipeline site in Cannon Ball, N.D., on Dec. 1, 2016.

Protesters sled down a hill at the Oceti Sakowin camp in Cannon Ball, N.D., on Dec. 2, 2016.

An American flag quilt lays in the back of a veteran’s car at the Oceti Sakowin camp where people have gathered to protest the Dakota Access oil pipeline in Cannon Ball, N.D., Friday, Dec. 2, 2016.