Although the March for Life in Washington, D.C., every Jan. 22 to mark the anniversary of Roe v. Wade is the best-known event of its kind, there are several other "younger" marches across the country that are gradually building greater followings.

One of the newer is in San Francisco. Begun in 2005 with 8,000 people, the march through the City by the Bay last year drew about 25,000 marchers.

This year organizers have upped the ante, with the launch Dec. 31 of a 20-foot-by-60-foot billboard next to the approach of the San Francisco-Oakland Bay Bridge, one of the most heavily traveled spans in the world, carrying 270,000 vehicles daily.

The billboard (www.walkforlifewc.com) advertises the Jan. 24 march and provides a post-abortion support hot-line number. The hotline is staffed by women who also have had an abortion, organizers said.

"San Francisco is a beautiful city, but there is a lot of sadness beneath the surface," said Eva Muntean, Walk for Life co-chair.

"Until recently we had more abortions than live births, and a high percentage of our population has experienced abortion," she said. "We need to reach those women -- and men -- who are hurting, and this seemed like the most effective method."

The roughly four-mile route starts in the city's downtown area.