Thousands of volunteers gathered at the Los Angeles River recently for an annual cleanup of the urban waterway. Many residents know the river as a concrete drainage channel, but a major effort is underway to restore it to its natural state.

Flood control channels encase the Los Angeles River, which is dry for most of the year but springs to life forcefully when the winter rains begin in November and December. Each April, as the waters subside, volunteers like Sigita Saliklis clean up the trash caught in the vegetation during the winter.

"It is probably 99 percent plastic bags," said Saliklis. "The rest is cans or plastic cups."

Larger items find their way here as well, says clean-up volunteer Julie Colomes.

"Hoses, bike parts, mattresses, clothes. I have got a couple of jeans. So it is a lot of stuff and I am glad it is getting cleaned," Colomes noted.

The wildlife is coming back, says California State Senator Kevin de León, who supports the river revitalization.

"You see the beautiful birds that are on this river, and it is like they are not waiting for any politicians, either at the local, state or federal level. Nature is busting through this concrete," said De León.

Melanie Winter of the environmental group The River Project says the elements of this river form a watershed, an ecosystem that purifies the water naturally.

"Soil matrix, plants, those all do a good job of helping to clean out water pollution, so the benefits go on and on and on," Winter said.

The L.A. River cleanup took place on a National Day of Action, called by the non-profit organization Keep America Beautiful. Paul Racs is with the Los Angeles Office of Community Beautification.

"Throughout the country, there are thousands of volunteers that are coming out and participating in community cleanup and beautification programs," said Racs.

The federal government is also supporting river restoration in many Americans cities. This project is special for Pauline Louie of the Los Angeles office of the U.S. Department of Housing and Urban Development. She grew up near the river.

"Not only from a professional standpoint, but from a personal standpoint, I feel vested in
taking this on as a personal contribution to seeing the LA River become all that it can be," said Louie.

In Los Angeles, this day of service brings people together around the river, says the founder of the group Friends of the Los Angeles River, Lewis MacAdams.

"And instead of being a divider of the city, it becomes a gathering place, like the old gospel song goes, 'We will meet you down by the river,'" said MacAdams.

These volunteers hope to make the 80-kilometer urban waterway an important part of the Los Angeles landscape, as it was in the city's early days two centuries ago.