'1923' star Aminah Nieves breaks down how she and her Native American costars recovered after filming some of the 'Yellowstone' prequel's most harrowing scenes: 'We'd cry it out together'

• Warning: There are spoilers ahead for the season one finale of Paramount+ drama, "1923."
• Aminah Nieves told Insider that she found it "very hard" to decompress after difficult scenes.

"Yellowstone" is known for not shying away from scenes of extreme violence, and the newest chapter in the Dutton history book, "1923," has proven to be no different.

Over the course of its eight-episode first season, audiences have seen Teonna Rainwater (Aminah Nieves) suffer horrifying physical, emotional, and sexual abuse at a Catholic boarding school run by the sadistic Father Renaud (Sebastian Roché).

Sitting down virtually with Insider ahead of the finale, Nieves broke down how she decompressed after long and sometimes arduous days on set, and Teonna's mindset ahead of season two.

At the beginning of the "Yellowstone" prequel's season finale, audiences catch up with the young Native American teenager after she has collapsed into bed following a violent and exhausting showdown with two of the priests who managed to track her down across the Dakota badlands. While she managed to get the better of them in the end, Hank (Michael Greyeyes) was shot during the fight and killed instantly.

"She's hurt. She's physically, mentally, and spiritually hurt," Nieves said of her character at this moment, describing Hank's death as "the last straw for Teonna, truly."

Indeed, Hank is the third person Teonna has lost since rebelling against her captors and escaping her residential school, as her grandmother Issaxche (Amelia Rico) and cousin Baapuxti (Leenah Robinson) have also become victims of the callous cruelty of the prevailing church and state at the time and are killed indiscriminately for not knowing Teonna's whereabouts.

When the cameras stopped rolling and it was time for Nieves to pull herself out of Teonna's heartwrenching story, the actor said she found solidarity and support from others on set, namely her costars Robinson, Greyeyes, Cole Brings Plenty, and Michael Spears.

"We had really late nights and long long days," Nieves said of her on-set support network. "So I just literally turned to others and we would just we would talk it out, we would hug it out, and we'd cry it out together."

Nieves also said she was also consoled by Cole's uncle, Mo Brings Plenty, who stars in "Yellowstone," and his wife Sara Ann Brings Plenty, who worked as American Indian Affairs Coordinator on "1923," as well as Birdie Real Bird, who is credited as the show's Crow language interpreter.

"But really, I built a boundary for myself and once it was done, I had to be done," she continued, adding that she was "pretty good" at making sure she never pushed herself past her boundaries.

"It was still very hard," she recalled, and that's when she said she would turn to medicine and rest to ensure that she was able "to do it all again the next day."

"I think I was always pushing myself to my limits," she said. "But also making sure that I wasn't getting caught in those spaces fully. I wanted to make sure I was always protecting myself as well."

"You had to push yourself and go to places that you necessarily wouldn't go to in another role because they're important," the actor, who is of Indigenous descent, continued. "The last thing that I wanted to do as Aminah was to not get it right."

Nieves pointed to the fact that she meticulously studied Crow, a language spoken primarily by the Apsáalooke people native to Montana, to play Teonna, who comes from the Big Sky state's fictional Broken Rock Reservation.

"It's not my native language," Nieves said. "So I spent time with Birdie as I wanted to make sure I got every single thing right. I was always asking her, 'Okay, does it sound okay? Do I need to go faster? Do I need to go slower?'"

As "so many Indigenous languages have gotten unremembered," Nieves said she really wanted to make sure she got it right out of respect.

Nieves previously told Insider that portraying the systematic oppression that Indigenous American people went through is "necessary" even if it is hard to watch.

"I think it's necessary because this hasn't been told as truthfully and on this wide of a scale before," Nieves said when asked about the staggering amount of violent acts carried out against her character.

She continued: "Truly, I think that we have to speak up and we have to share these stories no matter how hard they are."

Nieves added that as the show presumably "has more of a white demographic," it's even more important that the show doesn't "shy away from" graphically violent or emotionally troubling scenes so that viewers learn about the injustices Indigenous people suffered.

"1923" is now streaming on Paramount+.