GLENDALE >> Elizabeth Hord picked her way Saturday beneath the willows of the upper Los Angeles River, plucking out paper cups, Styrofoam burger boxes and man-made bits from the mud.

Thus began the 27th Great Los Angeles River Cleanup, billed as the largest urban river scouring in America.

“We have less and less trash every year,” said Hord, 65, of Hancock Park, a volunteer for Friends of the Los Angeles River, hoisting up her river haul below the Bette Davis Picnic Area near Glendale. “It’s a great way to spend a Saturday morning.

“It’s non-threatening. It helps the river. This place has so much potential. It gets better year after year.”

The massive cleanup at 15 sites along the 51-mile LA River during the last three Saturdays in April is expected to draw some 9,000 bag-carrying volunteers — double last year’s participants, who scraped 40 tons of trash from the waterway.

During the 9 a.m. to noon cleanup across the San Fernando Valley Saturday, an estimated 3,000 volunteers waded into the weeds of the upper river’s natural bottoms of Griffith Park, the Glendale Narrows Riverwalk, Big Tujunga Wash and the Sepulveda Basin.

Next Saturday, they’ll scour the middle river around the Glendale Narrows, through Atwater Village and Griffith Park.

Then they’ll traipse into the lower river April 30 to skim detritus out of Lower Compton Creek, Willow Street Estuary and the Golden Shore Marine Reserve near Long Beach.

Volunteers can sign up at https://folar.org/cleanup/.

It was three decades ago that poet Lewis MacAdams founded his Friends of the LA River with an outdoor fundraiser on the Bette Davis glade. Someone brought a kayak, and they had to dredge the dirty river for an effective run.

Since then, the nonprofit group has worked to restore the mostly concrete river into a swimmable, fishable, boatable and bikeable riverway. Plans call for restoring an 11-mile stretch north of downtown in hopes of attracting steelhead trout. The cost: $1.1 billion.

A cleanup crew of more than 150 volunteers descended on a bright, warm morning into the trapezoidal expanse below the Griffith Park picnic area, where baby ducks swirled ahead of pink-legged water birds amid the hum of the nearby 134 Freeway.

“The awareness of the river, the fact that people are starting to look at this as a vital piece of the eco-structure, is showing,” said Friends of the LA River Chief Operating Officer Andrea White-Kjoss, wearing a blue 30th-year commemorative T-shirt given to volunteers.

That’s where Hord and her friend Mark Chavez had beat the cleanup battalion.

By 9:05 a.m., the 61-year-old Chavez had already filled up a plastic bag, his hands deftly pulling threads from the LA River mud.

“Look at this,” Chavez said, dredging what appeared to be a golf bag, followed by a golf shirt, followed by a golf ball. “I think in general, it makes me feel good to pick things up. But it frustrates me, too, that people don’t take better care of our environment.”

“I can’t believe what people do to the river,” said Debbi Converse, of Pasadena, in knee-length rubber boots, pulling out a gleaming gold and silver bighorn sheep statuette. “This is a pride point for Angelenos.

“So we want it to look good.”