NEAR CANNON BALL, N.D. — When visitors turn off a narrow North Dakota highway and drive into the Sacred Stone Camp, where thousands have come to protest an oil pipeline, they thread through an arcade of flags whipping in the wind. Each represents one of the 280 Native American tribes that have flocked here in what activists are calling the largest, most diverse tribal action in at least a century, perhaps since Little Bighorn.

They have come from across the Plains and the Mountain West, from places like California, Florida, Peru and New Zealand. They are Oglala Lakota, Navajo, Seneca, Onondaga and Anishinaabe. Their names include Keeyana Yellowman, Peter Owl Boy, Santana Running Bear and Darrell Holy Eagle.

Some came alone, driving 24 hours straight across the Plains when they saw news on social media about the swelling protest. Some came in caravans with dozens of friends and relatives. One man walked from Bismarck.

Others finished the journey in canoes. They brought ceremonial pipes, dried sage, eagle-feather headdresses and horses that they ride bareback through the sea of prairie grass. They sleep in tepees, camper trailers and tents, and they sing and drum by firelight at a camp that sits on Army Corps of Engineers land.

On Friday, the federal government announced that it was temporarily blocking construction of the pipeline at an important river crossing just up the road from the camp.

“We say ‘mni wiconi’: Water is life,” said David Archambault II, the chairman of the Standing Rock Sioux, whose reservation sits just south of the pipeline’s route. “We can’t put it at risk, not for just us, but everybody downstream.”

He added: “We’re looking out for our future, the children who are not even born yet. What is it they will need? It’s water. When we start talking about water, we’re talking about the future generations.”

Here are stories about a few of the people who have come to this remote rolling corner of North Dakota.