1. A group of the Fort Laramie treaty riders head out in the morning along the local highway on the Cheyenne River Reservation outside of Bridger, South Dakota, on April 16, 2018.

2. Stephanie Big-Eagle rides with other Fort Laramie treaty riders along Bombing Range Road on the Pine Ridge Reservation near Scenic, South Dakota, on April 20, 2018.

3. Ivan Lookinghorse (center) and other Fort Laramie treaty riders meet in the kitchen of the Rockyford School gymnasium on the Pine Ridge Reservation on April 20, 2018. "Understand that we, as a people, we have been in poverty, we have been in depression, we have been Christianized, we have been boarding schooled, our language has been taken away from us, but we are on our way back to who we once were," Lookinghorse said. "We are standing up on our two feet," he continued. "We are taking our place in the world, the protectors of the Grandmother Earth."

4. Wes Redday from the Cheyenne River Reservation holds a sacred staff during a morning prayer near an encampment for the Fort Laramie treaty riders in Chadron, Nebraska, on April 23, 2018.

5. A small herd of buffalo grazes near the Sage Creek campground in the Badlands National Park outside of Wall, South Dakota, on April 19, 2018.

6. Tatanka Itancan Lone Eagle, 15, from Bridger on the Cheyenne River Reservation, hugs his horse at the end of the day during the Fort Laramie treaty ride in Scenic, South Dakota, on April 19, 2018.

7. The Fort Laramie treaty riders come off the trail and ride past a housing cluster on the Pine Ridge Reservation as the sun sets in Oglala, South Dakota, on April 21, 2018. The forward-most rider carries a sacred staff. Tradition dictates that all the riders ride behind the person carrying the sacred staff. There may be more than one sacred staff, as people might bring a staff to represent their community.

8. Wyatt Grey is seen by the light of a campfire during an overnight stop for the Fort Laramie treaty ride in Harrison, Nebraska, on April 24, 2018.

9. A woman wearing a sweatshirt that reads "Defend the Sacred" waits for the arrival of the Fort Laramie treaty riders for a rest stop near Harrison, Nebraska, on April 24, 2018.

10. Maske Ahwe Chu Kinya Plenty Chief, 14, from Eagle Butte on the Cheyenne River Indian Reservation (top) wrestles with some of the Fort Laramie treaty riders as they play games together in their communal camp in Harrison, Nebraska, on April 24, 2018.

11. Duane Blindman, 64, of the Oglala tribe, from Slim Buttes on the Pine Ridge Indian Reservation, poses for a photograph in Van Tassel, Wyoming, on April 25, 2018. The area of Slim Buttes is located in the southwest portion of South Dakota and these riders joined the group as the ride passed through their area.

12. The back of a horse belonging to one of the Fort Laramie treaty riders is seen during a break in Torrington, Wyoming, on April 26, 2018.

13. Roderick Dupris (center on a white horse), 45, from Bridger on the Cheyenne River Reservation, rides with other Fort Laramie treaty riders along Van Tassel Road in Torrington, Wyoming, on April 26, 2018.

14. Fort Laramie treaty riders can be seen travelling on a road as they make their final approach to Fort Laramie just outside of Fort Laramie, Wyoming, on April 27, 2018.

15. A horse is decorated with a handprint before heading into the town of Fort Laramie on April 27, 2018.

16. The Fort Laramie Treaty riders take a break after arriving at the Fort Laramie National Historic Site in Wyoming on April 27, 2018.

17. Lucille Contreras, one of the Fort Laramie treaty riders, from the Pine Ridge Reservation, poses for a photo in the tribal area on the grounds of the Fort Laramie National Historic Site on April 29, 2018.

18. Fort Laramie treaty riders return from crossing a creek in the tribal area on the grounds of the Fort Laramie National Historic Site on April 29, 2018.

19. Phil Little Thunder from the Rosebud Reservation wears his ceremonial outfit in the tribal area of the Fort Laramie National Historic Site on April 29, 2018. The tribal area was a large field organized into smaller camps according to a tribe, like the Oglala camp, the Rosebud camp, and the Cheyenne River camp, among others.

20. On the Cheyenne River Reservation in Green Grass, South Dakota, Cody James Lookinghorse (left) and Maryann Lara (right) play in front of the home of Beatrice Lookinghorse on April 30, 2018. Beatrice Lookinghorse is related to several of the Fort Laramie treaty riders who live with her. Beatrice also raises other children from the extended Lookinghorse family. "I promised my father that none of his grandkids would ever be put in the [foster-care] system," she said.

21. Beatrice Lookinghorse sits with two of her grandchildren, Linda Lookinghorse and Cody James Lookinghorse, in the backyard of her home on the Cheyenne River Reservation in Green Grass, South Dakota, on May 28, 2018.

22. Some of Arvol Lookinghorse's horses are chased across a field on the Cheyenne River Reservation in Green Grass, South Dakota, on May 28, 2018.

23. Cody Lookinghorse plays in the backyard of Beatrice Lookinghorse's home on the Cheyenne River Reservation on May 29, 2018.

24. A group of young people, either part of the Lookinghorse family or affiliated with it, sit on the porch of Arvol Lookinghorse's house on the Cheyenne River Reservation on May 29, 2018.

25. Jayden Lookinghorse wins a horse race against his cousins and friends in the driveway of Arvol Lookinghorse's home in Green Grass, South Dakota, on May 29, 2018.

26. Jayden Lookinghorse, riding his horse, stands on top of a hill at Arvol Lookinghorse's home on the Cheyenne River Reservation on May 30, 2018. Parts of Arvol Lookinghorse's land are considered to be very sacred and to be the spiritual center of the Lakota Nation, and Arvol Lookinghorse is the "keeper of the sacred bundle," a sacred collection of artifacts for the Lakota people. Many Lakota people and other pilgrims come to this land for religious ceremonies and guidance.

27. Angel Rose Lookinghorse, sitting with her younger cousins, Linda Lookinghorse and Maryann Lara, speaks to her brother, Jayden Lookinghorse, riding his horse, on the Cheyenne River Reservation in Green Grass, South Dakota, on May 31, 2018.

28. Horses run through a river near Arvol Lookinghorse's home on the Cheyenne River Reservation on May 30, 2018.

29. One of Beatrice Lookinghorse's granddaughters, Rozelynn Whitebull, plays near an abandoned house in the backyard of Beatrice Lookinghorse's trailer on the Cheyenne River Reservation on May 31, 2018.

30. Mahto In The Woods jumps over a small creek on foot while his cousin Jayden Lookinghorse jumps over on his horse in Green Grass, South Dakota, on May 31, 2018.