Feb. 5, 2010 -- Winston Blackmore, head of Canada's largest polygamist group, has an estimated 25 wives plus 121 children. And despite criticism of plural marriages, the group says polygamy is as moral a lifestyle as any other, which it's determined to prove to the world.
Blackmore's 11th wife, Zelpha Chatwin, is the mother of his latest child, Jedediah Mike Blackmore. She defended her fundamentalist community.
"Having a sister-wife, it's like having the same relationship with your husband, but it's just two women, or three women or four, instead of a man and a woman," said Chatwin, who is the mother of seven children. "I love these girls. … And I couldn't live without them. I really couldn't."
Chatwin and her extended family will be featured in National Geographic magazine and on the National Geographic Channel.
"Inside Polygamy" premieres Feb. 10 on the channel. There'll be more on the story in the magazine's February issue.
The tight-knit polygamous community of Bountiful located near Creston, British Columbia, faces a unique set of challenges.
Realities of Plural Marriage
Blackmore wouldn't confirm how many wives he has but Chatwin's sister, Marsha, is his 10th.
The sisters became his wives on the same day. As for plural marriages, Marsha Chatwin said, there's "definitely jealousy."
Blackmore's second daughter, Mary Roundy, said her particular family didn't get a lot of time with Blackmore.
"But whenever he'd do things with us, it would be really special," she said.
Roundy is making her own life choices within the community that's estimated at 500 strong.
She's in a monogamous marriage with a man who was also raised in a polygamous family.
"Even with my father's children, most don't seem particularly interested in living that lifestyle," she said. "I don't see it dying out right away. Maybe a few generations. Who knows?"
Until 2001, Blackmore's group followed Warren Jeffs, the "prophet" and leader of the Fundamentalist Church of Jesus Christ of Latter Day Saints, or FLDS.
'Prophet' Jailed, Group Renounces Underage Marriages
But Jeffs is now in prison, serving multiple sentences after his conviction connected to underage marriages, some to girls as young as 12. He is on suicide watch.
Texas Child Protection officials took 439 children into custody from a ranch run by the FLDS in a 2008 raid, saying underage girls were being married off to older men and that the sect's boys were being raised to become sexual predators.
In the largest child custody case in U.S. history, the Texas Supreme Court ordered hundreds of children from the sect, who had been held in state custody for a month, to be returned to their parents, agreeing with a lower-court decision that the state had not proved that the children were in immediate danger of abuse.
Twelve FLDS men from Texas have been indicted on a variety of sex charges, including assault and bigamy.
Sect leaders have promised there will be no more underage marriages.
"Inside Polygamy" premieres Feb. 10 on the National Geographic Channel.
You can read more about the story in February's issue of National Geographic magazine.
ABC News' Ryan Owens contributed to this story.