RIVERSIDE – Almost 1,250 of the roughly 11,000 same-sex couples who have gotten married since such unions were legalized in California in June tied the knot in Riverside County, according to a study released Monday.

Riverside County's total was fourth-highest in the state, the Williams Institute at the UCLA School of Law reported.

Los Angeles County topped the list with 2,719 same-sex unions, followed by San Francisco County with 2,708, San Diego County with 1,689, Riverside County with 1,247 and Alameda County with 475.

Together, the five counties accounted for 80 percent of the state's same-sex marriages, according to the report.

Researchers credited the counties' “large and visible” lesbian and gay populations, as well as the the fact that they make attractive tourist destinations for out-of-state couples wanting to get married.

The California Supreme Court overturned the state's ban on gay marriage in May after a lengthy court battle.

Gay marriage became legal at 5:01 p.m. June 16, prompting same-sex couples throughout the state to flock to county clerk offices to apply for marriage licenses.

Opponents of same-sex marriage fired back by petitioning for an amendment to the state constitution to declare than only marriage between a man and a woman be valid in California.

The amendment, Proposition 8, will go before voters at the Nov. 4 General Election.

Researchers at the Williams Institute also published three other studies on the demographics of same-sex couples in California. Key findings include:

 nearly 25 percent of the couples are raising children, totaling 52,000 kids;

 there are 109,000 same-sex couples in California, up from 90,000 in 2000;

 California is home to the largest percentage of same-sex couples; and

 861,000 lesbian, gay and bisexual adults live in California.