The marches were the latest of several demonstrations held throughout the state this week after the passage of Proposition 8, which would amend the California Constitution to define marriage as between a man and a woman. The measure overrides a state Supreme Court ruling in May that briefly gave same-sex couples the right to wed.
In Salt Lake City, a crowd of about 2,000 chanted "Separate church and state" and waved rainbow flags outside the headquarters of the Church of Jesus Christ of Latter-day Saints, which encouraged its members to work to pass the amendment by volunteering their time and money for the campaign.
Some protesters held signs with messages like, "Mormons: Once persecuted, now persecutors." Church officials offered no statement on the rally and march Friday night, but had called for civility and respect before and after Tuesday's vote.
The protest in Long Beach attracted about 2,000 people who were escorted by police as they marched through streets chanting and holding signs in support of gay rights.
Police said the march was peaceful, though there were some verbal clashes between gay rights activists and supporters of Proposition 8. Three people were arrested for trying to lead protesters past police lines.
The demonstration in San Francisco included about 1,000 protesters escorted by police who marched down Market Street during rush hour and ended at City Hall. No arrests were reported.
Lisa Davis, 42, among the protesters on Market Street, held a sign that read, "You gave rights to chickens and took away rights from human beings." The sign referred to the passage of Proposition 2, which requires better treatment of farm animals.
As the protesters made their way southwest on Market Street towards Castro Street around 6 p.m., some joined hands across Market at Ninth Street, reports CBS affiliate KPIX-TV in San Francisco. The barrier stopped traffic for more than an hour, causing honks from vehicles, some in support and others in annoyance and an urgency to get past.
Those who made it to Dolores Park chanted, played music and danced, prompting the temporary closure of Dolores Street at 19th Street.
Police Lt. Neville Gittens said three people were arrested for being drunk in public but added that they did not appear to be part of the protest, just observing.
Gittens said that by about 8 p.m. the protest broke up peacefully.
Davis said she planned to propose to her girlfriend during the march.
According to the CBS News Election and Survey unit's analysis, black voters overwhelmingly voted in favor of Prop. 8 - by a 70 percent to 30 percent margin. Hispanic voters overall favored the measure as well but only by a 53 percent to 47 percent margin. White voters were slightly on the side of approving it, 51 percent to 49 percent.
There is disappointment that the African-American community, which just saw the election of the first black president, voted overwhelmingly against same-sex marriage, reports CBS Early Show correspondent Hattie Kauffman.
Gay rights groups and same-sex marriage proponents have filed at least three court challenges against the ban.