County clerks across Washington state braced on Wednesday for a flood of marriage-license applications from gay and lesbian couples eager to exchange vows once a new law legalizing same-sex matrimony takes effect at the stroke of midnight.

Washington made history last month as one of three U.S. states where marriage rights were extended to same-sex couples by popular vote, joining Maryland and Maine in passing ballot initiatives on November 6 recognizing gay nuptials.

Washington will be the first of those states to put its law into effect on Thursday. Same-sex matrimony goes on the books in Maryland and Maine on December 29 and January 1, respectively.

Under Washington state law, all would-be brides and grooms must submit their marriage certificates at least three days in advance. So the first wave of same-sex Washington weddings - expected to number in the hundreds - is scheduled for Sunday.

In Olympia, the state capital, the Thurston County Auditor's Office planned to open at midnight to grant marriage licenses to the 15 same-sex couples who entered a lottery to be served first. The office will reopen at 7 a.m. to serve others.

"It's exciting," said Thurston County Auditor Kim Wyman, a Republican. "This is a moment people will look back at years from now. I think it's important to acknowledge and celebrate it."

Lisa Brodoff and Lynn Grotsky will be the first same-sex couple in Thurston County - and perhaps the state - to receive a marriage license.

"It's a feeling of unmitigated happiness," said Brodoff, 57, a law professor at Seattle University. "We've been together almost 32 years and we've looked forward to and hoped for this day for virtually the entire time we've been together."

SAVING THAT DATE

Brodoff said she and Grotsky, 56, could have tied the knot in one of the six states where same-sex marriage was already legal, but they wanted to wait until they could marry in their home state.

In Seattle, King County offices were also slated to open at midnight to serve same-sex couples seeking marriage licenses and planned to stay open late, until 6:30 p.m., on Thursday, in anticipation of a surge. About 140 couples were already expected to show up at City Hall in Seattle for weddings being held there on Sunday.

In Tacoma, Pierce County will open its doors at 6:30 a.m. on Thursday, two hours earlier than usual, and will provide weekend hours, as well.

"We expect we'll have a large crowd," Pierce County Chief Deputy Auditor Lori Augino said. "We're prepared to help upward of 150 couples (on Thursday), whether they show up or not."

While heterosexual couples face difficulties enough picking an ideal time and place for their nuptials, the fraught politics of same-sex marriage in Washington state made it much trickier for gay and lesbian couples to plan ahead.

The Democratic-controlled state Legislature passed a bill to legalize gay marriage in February, and Democratic Governor Christine Gregoire, swiftly signed it into law.

But opponents collected enough signatures to temporarily block the measure from taking effect and force the issue onto the state ballot in November.

Voters passed it by 54 percent to 46 percent.

Olympia residents Tina Roose and Teresa Guajardo said they would wait until December 15 to marry, having reserved the majestic Capitol rotunda for a pre-Christmas wedding ceremony.

The uncertainty of the ballot initiative process proved a bit of a nail-biter as Roose and Guajardo waited for the election results to see if they could keep their reservation.

"We had faith in the voters of Washington," Roose said, adding they had invited other couples, both gay and straight, to tie the knot alongside them at the Capitol.

As for those who voted against same-sex marriage, Roose said she hoped they would be won over "with love."

"You can only change people's attitudes one heart at a time," she said.