Shailene Woodley spent Thanksgiving alongside hundreds of protesters opposing the Dakota Access pipeline at the Standing Rock Sioux Reservation.

The 25-year-old outspoken actress spoke with TYT Politics on Thursday, fighting back tears as she criticized the American holiday.

WATCH: Shailene Woodley Arrested at Protest Over Dakota Access Pipeline

"I do know that today is a day that many call Thanksgiving, and it's a day where kids in elementary school and America are taught false narratives about our native brothers and sisters," she explained in a video posted to Facebook. "From the time we were little kids, we'd caught out in cardboard paper pictures of pilgrims and feasts and turkeys. And yet none of our children know the truth about not only what happened to Native Americans, when westerners decided to colonize this country, but what is still happening to Native Americans."

"This pipeline, and I know this has been said, but like, gosh, this pipeline was supposed to be built in Bismarck, North Dakota," she continued. "Which is a predominately white 'American' area. And when the people of Bismarck decided that if this pipeline -- when this pipeline breaks -- it would compromise the integrity of their water. They moved it to the Native American reservation. They didn't do it, they failed to, and we're still here, on Thanksgiving, again the day that no one knows the history about."

"Thanksgiving was founded on a massacre," she added. "And yet we're here with these cops, with snipers with rubber bullets, and I'm honest -- I'm just sick of it. There is no excuse. Where is everyone? Why isn't everyone standing up and saying something?"

WATCH: Shailene Woodley Pleads Not Guilty to All Charges in Dakota Access Pipeline Arrest

Woodley, who was joined by actresses Nikki Reed and Jane Fonda, later took to her own Facebook page to share a few additional videos filmed live from the reservation. "I just invite every single person who's watching from home to investigate and research what this holiday means, why this holiday exists and what you're going to do to reframe that narrative, and to change that narrative, for your future ancestors," the "Snowden" star urged her followers.

She also shared a photo from Sunday night "when protectors were sprayed in subzero temperatures with water, tear gas, mace, rubber bullets, bean bag bullets, percussion grenades."

According to The New York Times, federal officials plan to close access to the protest campsite, citing safety concerns. The authorities will close the area north of the Cannonball River, the NYT reports, including the Oceti Sakowin camp, about 40 miles south of Bismarck, where opponents of the 1,170-mile Dakota Access Pipeline have gathered for months. Anyone found on the land after Dec. 5 could be charged with trespassing.

WATCH: 'The Avengers' Stars Band Together to Stand With Standing Rock

"It is both unfortunate and disrespectful that this announcement comes the day after this country celebrates Thanksgiving, a historic exchange between Native Americans and the first immigrants from Europe," Dave Archambault II, chairman of the Standing Rock Sioux Tribe, said in a statement. "Although the news is saddening, it is not all surprising given the last 500 years of mistreatment of our people."

Back in October, Woodley was arrested for criminal trespassing while protesting the construction of the project. She has pleaded not guilty to criminal trespass and engaging in a riot, both misdemeanors that carry a maximum punishment of a month in jail and a $1,500 fine.

"One day, baby, we'll sing our poetry. the words dripping from our tongues wet with ripened patience," she wrote on Instagram one day after her arrest. "And the lyrics, the sweet fruits born from the seeds our aging hands are now sowing. #alwaysinallways #heartforward #uptous #NoDAPL #protectcleanwater #iamonyourside."|

As ET previously reported, the peaceful protest, which was streamed on Facebook Live, followed a federal judge's ruling on Sunday that rejected the Standing Rock Sioux Tribe's request to halt construction on the pipeline, which they claim will destroy sacred sites and contaminate ground water.

WATCH: Shailene Woodley Breaks Her Silence After Being Arrested While Protesting the Dakota Access Pipeline

Woodley and other protestors joined the tribe to stand against the $3.8 billion pipeline, which will span 1,100 miles across North and South Dakota, and into the Missouri River.