COLORADO CITY, Ariz. — For half a century, while polygamous members of this remote enclave engaged in widespread sexual abuse and child exploitation, government authorities on all levels did little to intervene or protect generations of victims.

Here in the sparsely populated canyon lands straddling Arizona and Utah, members of the Fundamentalist Church of Jesus Christ of Latter-day Saints, or FLDS — an offshoot of Mormonism — live by their own rules.

The religious sect of about 10,000 portrays itself as an industrious commune of the faithful, choosing to live apart from a hostile world. But their simple lifestyle and self-imposed isolation have concealed troubling secrets that are only beginning to emerge.

Court records, undisclosed investigative reports and interviews by The Times over the last year show that church authorities flout state and federal laws and systematically deny rights and freedoms, especially to women and children.

"The fact that this has been going on all these years, and the fact that justice has not been there to protect women and children … from amazing civil rights violations — it is an embarrassment," said Utah Atty. Gen. Mark Shurtleff.

"I don't want to indict the states of Utah and Arizona, but mea culpa — we are responsible."

Among sect members, girls as young as 13 are forced into marriage, sexual abuse is rampant, rape is covered up and child molesters are shielded by religious authorities and law enforcement.

Boys are thrown out of town, abandoned like unwanted pets by the side of the road and forcibly ostracized from their families to reduce competition among the men for multiple wives.

Children routinely leave school at age 11 or 12 to work at hazardous construction jobs. Boys can be seen piloting dump trucks, backhoes, forklifts and other heavy equipment.

Girls work at home, trying to keep order in enormous families with multiple mothers and dozens of children who often eat in shifts around picnic tables.

Wives are threatened with mental institutions if they fail to "keep sweet," or obedient, for their husbands.

Warren Jeffs, a wiry third-generation church member, is the sect leader — a post that carries the title "prophet" and gives him virtually absolute control over the most intimate conduct.

Jeffs orders marriages, splits up families, evicts residents and exiles whomever he wants with no regard for legal processes. He even tells couples when they can and can't have sex.

But Jeffs is now a fugitive, listed on the FBI's 10 Most Wanted list and accused by state and federal authorities of rape, sexual conduct with a minor, conspiracy and unlawful flight to avoid prosecution. Former members say he continues to exert influence nonetheless.

Some who fled the community in recent years are coming forward to tell investigators harrowing tales of repression and abuse inflicted behind a facade of pious devotion to faith and family:

•  Brent Jeffs reported being sodomized repeatedly at age 5 by the principal of his school — an uncle who would later become religious leader of the community — current fugitive Warren Jeffs.

•  Sara Hammon said her father, a prominent religious leader with 19 wives, routinely molested her, even sliding his hand up her dress while on his deathbed.

•  More than 400 boys, some as young as 13, have been thrown out of town for church infractions such as wearing short-sleeved shirts or talking to girls. Some, referred to locally as "Lost Boys," were dumped along the road with only the clothes they were wearing, and banned from contact with their families. Many of the displaced boys recently filed suit in state court against the church.

Despite years of such stories and allegations, public agencies on both sides of the state line have failed to act or been slow to intervene.