SALT LAKE CITY - A federal judge struck down Utah’s same-sex marriage ban Friday in a decision that marks a drastic shift toward gay marriage in a conservative state where the Mormon church has long been against it.

The decision set off an immediate frenzy as the clerk in the state’s most populous county began issuing marriage licenses to dozens of gay couples while state officials took steps to appeal the ruling and halt the process.

Cheers erupted as the mayor of Salt Lake City led one of the state’s first gay wedding ceremonies in an office building about three miles from the headquarters of the Mormon church.

Deputy Salt Lake County Clerk Dahnelle Burton-Lee said the district attorney authorized her office to begin issuing licenses to same-sex couples but she couldn’t immediately say how many had been issued.

Just hours earlier, U.S. District Judge Robert Shelby issued a 53-page ruling saying Utah’s law passed by voters in 2004 violates gay and lesbian couples’ rights to due process and equal protection under the 14th Amendment.

Shelby said the state failed to show that allowing same-sex marriages would affect opposite-sex marriages in any way.

“In the absence of such evidence, the State’s unsupported fears and speculations are insufficient to justify the State’s refusal to dignify the family relationships of its gay and lesbiancitizens,” Shelby wrote.

The decision drew a swift and angry reaction from Utah leaders, including Republican Gov. Gary Herbert.

“I am very disappointed an activist federal judge is attempting to override the will of the people of Utah. I am working with my legal counsel and the acting attorney general to determine the best course to defend traditional marriage within the borders of Utah,” Herbert said. The state filed a notice of appeal late Friday and was working on a request for an emergency stay that would stop marriage licenses from being issued to same-sex couples.

“It will probably take a little bit of time to get everything in place,” said Ryan Bruckman, a spokesman for the attorney general’s office. He said the judge told the attorney general’s office it would be a couple of days before any request for an emergency stay would be reviewed.

The ruling comes the same week New Mexico’s highest court legalized gay marriage after declaring the denial of marriage licenses to same-sex couples unconstitutional. A new law passed in Hawaii last month now allows gay couples to marry there.

Utah’s lawsuit was brought by three gay and lesbian couples. One of the couples was legally married in Iowa and just wants that license recognized in Utah. One of those couples, Moudi Sbeity and Derek Kitchen, were roasting eggplants for a farmers market today when their lawyer, Peggy Tomsic, called them with the big news.

“We had a positive feelingafter the hearing on Dec. 4, but it’s still a surprise to hear it,” Sbeity said. “We’re excited and happy and hopeful to see what happens what next.”

The couple, who own a company that makes Middle Eastern food spreads and sells them to supermarkets, won’t be getting married right away. They want to see if the state appeals.

Many similar challenges to same-sex marriage bans are pending in other states, but the Utah case has been closely watched because of the state’s history of staunch opposition to gay marriage as the home of Mormon church.

The church said in a statement Friday that it stands by its support for “traditional marriage.”

“We continue to believe that voters in Utah did the right thing by providing clear direction in the state constitution that marriage should be between a man and a woman, and we are hopeful that this view will be validated by a higher court,” the church said.

Tomsic applauded Shelby’s courage in making the ruling but warned that the legal fight is not over, saying she expects the state to take the case to the 10th U.S. Circuit Court of Appeals.

During this month’s hearing, Tomsic contended marriage is a fundamental right protected by the U.S. Constitution. She said Utah’s law, which passed with two-thirds of the vote, is “based on prejudice and bias that is religiously grounded in this state.”

In the ruling, Shelby wrote that the right to marry is a fundamental right protected by the U.S. Constitution.

“These rights would be meaningless if the Constitution did not also prevent the government from interfering with the intensely personal choices an individual makes when that person decides to make a solemn commitment to another human being,” Shelby wrote.

In New Mexico, a rural eastern New Mexico county clerk and her deputy resigned Friday rather than abide by the state Supreme Court ruling legalizing gay marriage, officials said.

Roosevelt County manager Charlene Webb confirmed that Clerk Donna Carpenter and Deputy Clerk Janet Collins announced their resignations Friday morning.

Webb declined to say why they quit. But county commissioners said it was in protest of Thursday’s Supreme Court ruling declaring it unconstitutional to bar same-sex couples from getting marriage licenses.

Commissioner Bill Cathey said the two had made it clear they would quit “rather than be associated with that.”

Roosevelt is a rural, conservative county along the Texas-New Mexico border. Its county seat is Portales, a town of about 12,000.

Cathey said Carpenter’s resignation was no surprise.

“She told us in the past that’s what she would do,” he said. “ I am personally very disappointed in the decision of the judges, and I don’t blame our clerk for doing what she did.” Information for this article was contributed by Jeri Clausing of The Associated Press.

Front Section, Pages 4 on 12/21/2013