Rebecca “Becky” Vance had an irrepressible urge, a genuine need to get away.

Despite little preparation and with amateur outdoor survival skills Vance, 42, convinced her Sister Christine last summer to “live off the grid” with her and her son in rugged western Colorado, leaving behind their lives in Colorado Springs.

Becky — said to be an anxious loner further exasperated by society during the pandemic — wanted to start anew by fleeing into the wilderness, where extreme weather and other potential pitfalls awaited in the Rocky Mountains. But she couldn’t be stopped, her stepsister told The Post.

“She was standoffish and an introvert, someone who liked to keep to herself,” Trevala Jara said Thursday. “But when she opened up, you had her heart. She’d do anything for anybody she loved. She loved life.”

Jara, 39, of Colorado Springs, said she and her husband pleaded with Becky to reconsider, but the last-ditch effort was fruitless. Becky, who refused to mention where she was headed, proceeded to venture off with her then-13-year-son and 41-year-old sister in early August 2022, Jara said.

The trio’s disconnection from civilization ultimately turned fatal, as a hiker found one of their “fairly mummified” bodies on July 9 near Gold Creek Campground in Gunnison County.

A day later, authorities discovered the other two corpses inside a blue tent, alongside empty food canisters and a makeshift shelter at the isolated encampment more than 100 miles away from their former home.

Becky was an intelligent outsider and fiercely protective of those she loved, Jara said. The single mother enjoyed reading and cooking, especially Korean fare, but wasn’t overly outdoorsy or even much of a hiker.

Trevala said she and her husband, Tommy, begged to get Becky to reconsider going “off the grid.

“It was definitely on top of my mind,” Jara said of the dangers that awaited her stepsisters and nephew, a homeschooled teen who has not been identified by authorities. “Me and my husband tried to stop them.”

Christine, 41, was more comfortable in the elements and more outgoing.

“She had a heart of gold,” Jara said, noting Christine was always ready to help anyone in need.

But Christine still had to be convinced by her older sister to set off into the wilderness.

“It was Becky’s idea,” Jara said. “At first Christine didn’t want to go, but she changed her mind. She felt like they had a better at living if she went with them. And she didn’t want our sister and nephew to be alone.”

Ann Kaskewicz can’t understand why her stepdaughters decided to get away from civilization. But as the older, dominant sister, Rebecca typically persuaded Christine in the end, she said.

“Becky was the leader,” Kaskewicz told the Colorado Gazette. “Christine would usually go along with whatever Becky said.”

Kaskewicz questioned how the sisters expected to endure Colorado’s harsh, unpredictable climate, especially throughout its 58 mountain peaks above 14,000 feet, as well as to feed themselves and a young teen.

She did not get clear answers from Becky, who simply “preferred to be alone most of the time,” Kaskewicz said. “And she didn’t trust anyone, including the government.”

Becky struggled with anxiety, but wasn’t “paranoid or out her mind,” Jara said, adding she believes her stepsister never sought mental health treatment.

Becky son, meanwhile, had mixed feelings about his mother’s plan to flee civilization, Jara said.

“He was scared and excited at the same time,” she continued. “He was only 13 when they left. He didn’t know what living off the grid entails at all, but he wanted to be with his mom.”

The trio set out without much preparation aside from watching YouTube videos on how to survive, Jara recalled.

The sisters and the boy lit fires inside their tent to stay warm and likely died sometime last winter,  Gunnison County Coroner Michael Barnes told the New York Times.

Toxicology tests will determine cause and manner of death for each victim.

“It could be another couple weeks,” Barnes told The Post.

Malnourishment and “exposure to the elements” during a harsh winter likely played a role, the coroner told the Colorado Sun.

Despite her ominous hunch that the open-ended excursion was a bad idea, Jara said she wasn’t prepared to learn her worst fears had been realized.

“I didn’t want to believe it, and it was really hard,” she told The Post. “There was a lot of screaming involved.”