The Cofers have been together for more than 10 years, but Sunday was the earliest time under the state's new law allowing same-sex marriage that they could legally wed.
The couple were married at the King County Courthouse by Judge Mary Yu, one of many local judges who are donating time to marry couples on Sunday.
Several other marriages were planned for the early-morning hours at the courthouse, giving same-sex couples the opportunity to get married as soon as possible after voters approved Referendum 74.
Gov. Chris Gregoire and Secretary of State Sam Reed certified the election on Wednesday afternoon, and the law took effect at 12:01 a.m. Thursday, when couples in Seattle lined up to pick up their licenses just after midnight.
Because the state has a three-day waiting period, the first weddings could not take place until Sunday.
At the Thurston County Courthouse five couples were married overnight, including Jonathon Bashford, 31, and Matthew Wiltse, 29, both of Olympia.
The couple, together for 10 years, just had a large commitment ceremony in September when they registered as domestic partners, but said they wanted to be among the first to legally marry.
"We weren't going to wait one second longer," Wiltse said.
In addition to private ceremonies that will start taking place across Washington state, about 140 couples had registered to marry at Seattle City Hall, which had set up five separate chapels to accommodate the revelers. Starting at 10 a.m., cheers and applause regularly broke out as another couple's marriage became official. Weddings at city hall were to continue through 5 p.m.
Mayor Mike McGinn, who greeted couples at they arrived, called it a "great day, a joyous day."
"It's really wonderful," he said. "A new civil right is going to be recognized in this great civil institution."
Keith Bacon and Corianton Hale of Seattle, who celebrated their six-year anniversary the night before, hugged and kissed to loud cheers and camera flashes as they took their vows.
"We're totally thrilled," Bacon said. The couple had done a commitment ceremony in August but said this day was particularly special.
"We had looked at this as maybe a day we would sign a piece of paper and seal the deal, and instead we're having this huge party being thrown in our honor," Bacon said. "It's just mind blowing."
The couple hugged and kissed to loud cheers and camera flashes as they took their vows.
Nancy Monahan, 57, a retired petty office with the Coast Guard, waited outside before the weddings began with her partner of 14 years, Deb Needham, 48.
Monahan was wearing her uniform, and Needham was wearing an ivory dress and jacket and matching hat. They said they wanted to join the large wedding event at city hall because of the significance of the day.
"It's not very private, but very historic," Needham said, to which Monahan added, "And very awesome."
Robin Wyss, of Seattle, said that the wedding ceremony to her partner, Danielle Yung, was "more emotional than I thought it would be," in part because Yung is five months pregnant.
"Our friends are here, it's a beautiful space and there's all of his love and appreciation," she said. "We've been thinking about this as more of a political celebration for all of Washington state, but obviously it's very meaningful for us and our future child as well."
Last month, Washington, Maine and Maryland became the first states to pass same-sex marriage by popular vote. They joined six other states - New York, Connecticut, Iowa, Massachusetts, New Hampshire, Vermont - and the District of Columbia that had already enacted laws or issued court rulings permitting same-sex marriage.
Couples in Maryland also started picking up marriage licenses Thursday, though their licenses won't take effect until Jan. 1. Maine's law takes effect on Dec. 29. There's no waiting period in Maine, and people can start marrying just after midnight.
Same-sex couples who previously were married in another state that allows gay marriage, like Massachusetts, will not have to get remarried in Washington state. Their marriages became valid here as soon as the law took effect.
The referendum had asked voters to either approve or reject the state law legalizing same-sex marriage that legislators passed earlier this year. That law was signed by Gregoire in February but was put on hold pending the outcome of the election. Nearly 54 percent of voters approved the measure.
The law doesn't require religious organizations or churches to perform marriages, and it doesn't subject churches to penalties if they don't marry gay or lesbian couples.
Married same-sex couples will still be denied access to federal pensions, health insurance and other government benefits available to heterosexual couples because the 1996 federal Defense of Marriage Act, known as DOMA, bars federal recognition of gay unions.
The U.S. Supreme Court on Friday said it will take up gay marriage sometime during the current term. Several pending cases challenge the federal benefit provision of DOMA, and a separate appeal asks the justices to decide whether federal courts were correct in striking down California's Proposition 8, the amendment that outlawed gay marriage after it had been approved by courts in the nation's largest state.