The group left behind farewell letters, personal documents and cash and took off into the night on a mysterious religious trip. After relatives reported them missing, authorities began a 22-hour search using horses, helicopters and patrols to comb the sprawling desert terrain around Palmdale as satellite trucks from national news outlets moved in.

Two scenarios loomed large, one unthinkable: a suicide pact that included eight children, inspired by the belief that the biblical “rapture” was upon them.

But relief set in Sunday as the second scenario prevailed: authorities found all 13 gathered comfortably at a manicured park less than 10 miles from a Los Angeles County sheriff’s station.

Reyna Marisol Chicas, 32, a Salvadoran immigrant identified as the group’s leader, offered up little to deputies Sunday, and initially gave authorities a different name when approached at Jackie Robinson County Park, east of Palmdale.

The other 12 members of the group, among them Chicas’ two children and six other minors, agreed to be taken to the Palmdale sheriff’s station, department spokesman Steve Whitmore said.

County child-welfare authorities have been brought into the case, and Chicas was being held Sunday for a 72-hour involuntary mental health evaluation, an official said.

The search began when concerned relatives contacted the Sheriff’s Department about 2 p.m. Saturday, saying they feared for their family members’ safety. Whitmore said the letters left by the group read like “a will and testament.” They were addressed to parents and other loved ones and included phrases like “Please take care of,” “Don’t worry,” “Here’s some cash,” he said. Letters written by two of the 14-year-olds were identical, which Whitmore said could indicate they were coached.

The group was found around noon, sitting on blankets laid out in the shade of a pine tree. A resident who had seen news reports on the missing group spotted them and called the Sheriff’s Department about 11:30 a.m.

Chicas was playing with some of the children on the swings, while the others sat on blankets praying, said sheriff’s Capt. Mike Parker. “They seemed shocked,” Parker said. “They said, ‘We are Christians, and we would never harm ourselves.’ ”

When deputies told them that notes and personal belongings they left behind had made relatives suspect otherwise, they responded by saying, “It’s sinful to have [worldly possessions] when you’re praying because they bring evil,” Parker said.

Far from spending the night in the dry, windy desert around Palmdale, as suspected, the group had slept at the home of Chicas’ friend, he said.

Authorities from multiple agencies devoted a massive amount of resources and time in the search effort, using helicopters, patrol cars and volunteer groups on horseback. “Could these people benefit from better communication with their family? Certainly.” Parker said.

The group drew the attention of one deputy well before they were reported missing. The patrol officer came across three cars occupied by several women and children, parked outside a Palmdale high school about 3 a.m. Saturday. When he asked what they were doing at the school at that hour, they said they were praying to end school violence and sexual immorality.

The group was known for previous forays into desert and mountain areas, apparently related to a belief in an imminent biblical “rapture,” in which believers would be transported to heaven. When found, group members, including children, called Chicas “their leader” and “an inspiration.”

The Palmdale area is home to several predominantly Latino churches, where it’s not uncommon for congregants to break off into separate prayer groups practicing nontraditional beliefs.

Although none of the 13, including Chicas, are facing criminal charges, Whitmore promised extensive follow-up on the case.

Ricardo Giron, a former neighbor of Chicas, said he was relieved, and not very surprised, to hear the group was safe.

“She’s always very careful with her kids,” he said. “I couldn’t believe she would hurt them.”

Chicas used to baby-sit Giron’s children, and their families vacationed together, he said. She had recently severed social ties with him as she grew increasingly religious, spending more time at a local church, he added. Giron said Chicas had left school after the fifth grade.

Whitmore said the Sheriff’s Department response, which included helicopters and volunteers on horseback, was warranted given the presence of children in the group.

robert.faturechi@latimes.com