Moab • On a Saturday in July, the sun shined on the redrock cliffs of southeastern Utah, and Heidi Foster sat on the banks of the Colorado River. She handed out fruit snacks to kids from polygamous families.

Foster, a plural wife from Taylorsville, was among about 130 people on a river trip. She brought five of her own children, and considered the rafting part of an important weekend in which her kids can drop their guard and be themselves.

“If someone asks, ‘How many moms do you have?’ you can tell them,” Foster said.

The rafting was one of the highlights of the annual Rock Rally, a five-day polygamous jamboree at Rockland Ranch, a community for polygamists about 40 minutes south of Moab. The rally included hiking, zip lining, river rafting and a dance with a country music band from Hildale, Utah, and Colorado City, Ariz., polygamous communities on the Utah-Arizona border.

The Rock Rally is a private gathering. Visitors need the consent of the hosts to attend. But every year, plural families sojourn at Rockland Ranch, where they carve out a place in a remote corner of the West for the rare acceptance of polygamy, even though the practice is illegal.

(Shannon Mullane for High Country News) The Fosters and other families blasted holes in sandstone before filling them with suburban-style homes at Rockland Ranch.

The best estimates put the population of so-called Mormon fundamentalists — those who practice polygamy — at approximately 35,000 people, most of whom live in the West. Their status as some of the region’s last outlaws means many polygamists live isolated lives.

The Rock Rally helps some polygamists meet and find someone to date. Polygamists’ family trees may be wide, but they aren’t necessarily tall.

Polygamist Valora Barlow, a plural wife who grew up in the Fundamentalist Church of Jesus Christ Latter-Day Saints in the community on the Utah-Arizona line, attended this year’s rally with her children. “I told my kids,” Barlow said, ‘“You can’t marry anybody that’s a Stubbs, a Darger, a Barlow, Johnson or Jessop.’ And they’re like, ‘Mom there’s nobody left.’ ”

(Shannon Mullane for High Country News) One teen gets a back massage while others chat during the testimony meeting at Enoch Foster's home at Rockland Ranch on July 28, 2019.

More than half a dozen polygamous churches were represented at the Rock Rally, including polygamists who do not affiliate with a church. Attendees came from at least five states and British Columbia. There also were a few monogamous members of The Church of Jesus Christ of Latter-day Saints, the mainstream faith headquartered in Salt Lake City.

Even though many followers of Mormonism can trace their theological roots to the same place, the various churches haven’t always gotten along. Disputes between the mainstream church and the various sects have caused schisms that led to numerous breakaway groups.

Many people, such as Barlow, have left the FLDS, the biggest and most infamous polygamous sect, led by Warren Jeffs, who is serving a sentence of life plus 20 years in prison for crimes related to sexually assaulting two girls he married as plural wives.

The FLDS was once thought to have 10,000 members. Those believers were prohibited from congregating with the other polygamous sects. All but about a couple thousand of Jeffs’ followers have left his sect.

In recent years, relations among the various Mormon-rooted sects have improved, and the Rock Rally gathering has continued to grow in recent years.

(Shannon Mullane for High Country News) Enoch Foster embraces his third wife, Lydia, left, and his second wife, Lillian, right, as she holds her son Elijah, during a closing hymn and prayer at the testimony meeting at Rockland Ranch on July 28, 2019.

Robert Foster founded Rockland Ranch in 1979 by detonating explosives into a rock owned by the Utah School and Institutional Trust Lands Administration. He built houses in the holes, and other families joined. Residents have since bought the property from the state. They jointly own and operate it as a nondenominational religious community. Robert Foster died in 2008.

His son, Enoch Foster, began the Rock Rally 15 years ago by inviting friends to ride dirt bikes and ATVs around Rockland Ranch. Some years, 500 people have attended the rally, Enoch Foster said. But the gathering remains relatively intimate, with the dates and schedule shared by word of mouth.

Last month, Foster and 130 people rafted the Colorado River, launching from a put-in northeast of Moab. The group meandered 13 miles down the river. Foster — playing a mixed role reminiscent of Moses from biblical times, plus modern outdoor adventurer and helicopter parent — climbed atop an enclosed cargo trailer to address the group.

“Welcome to the Rock Rally!” he yelled to cheers.

(Shannon Mullane for High Country News) Rally-goers look up at Enoch Foster, who is standing on top of a trailer, as he goes over rafting safety and logistics before leading a prayer near Moab, Utah, on July 27.

The river had only a few, light rapids. The bigger excitement came from kids and a few adults like Enoch Foster who jumped back and forth between rafts to throw people into the water.

About two hours into the float, the group pulled onto a bank. Volunteers flipped one raft into the sand and gathered to make and serve sandwiches.

The Rock Rally ended with a testimony meeting on Enoch Foster’s lawn.

Participants took turns in front of the group and articulated their relationship with Jesus Christ. As the meeting ended, Dougles Compton, one of Enoch Foster’s brothers-in-law, gave his testimony and said his goodbyes.

“I really enjoy seeing you,” Compton said, “and love you. We’ll see you next year.”

Editor’s note • This story was reported in collaboration with High Country News.