More than 65,000 volunteers are expected to turn out at beaches from Oregon to Mexico on Saturday for the 35th annual California Coastal Cleanup Day — a massive event that takes 2,500 miles of littered shorelines, including the shores of rivers, creeks and lakes, and turns them into gleaming landscapes.

The event runs from 9 a.m. until noon, and volunteers can still sign up by going to www.coastalcleanupday.org.

This year, however, there’s a new twist: It might be the last year where cigarette butts are the most numerous item picked up. Two bills to ban smoking at all state beaches — with a $25 fine for violators — have reached Gov. Gavin Newsom’s desk and await his signature.

Former Gov. Jerry Brown vetoed similar bills three times, saying people should be allowed to smoke outdoors in parks.

But this year there’s a new governor.

“I have been encouraged by the many conversations with the Newsom administration and am optimistic that he will finally place this ban into state law,” said State Sen. Steve Glazer, D-Orinda, who wrote one of the bills, SB 8.

The other measure is AB 1718 by Assemblyman Marc Levine, D-San Rafael. Under the identical bills, it would be illegal starting on Jan. 1 to smoke cigarettes, cigars, pipes, vaping devices “or any other lighted or heated tobacco or plant product intended for inhalation” on any state beach or in any state park in California.

The state Department of Parks and Recreation would be required to put up smoking signs at beaches and parks. It owns 280 miles of California’s coastline and operates 280 park units.

Supporters of the bills include the American Lung Association, the Sierra Club and other groups. They note that cigarettes contain dozens of cancer-causing chemicals, cause pollution, generate second-hand smoke and start wildfires.

A 2010 study by scientists at San Diego State found that when one cigarette butt was placed in a liter of water containing freshwater minnows and ocean smelt, half the fish died within 24 hours. Biologists also say cigarette waste can choke seabirds, turtles, fish and other wildlife when it is ingested.

The counties of San Mateo and San Francisco, along with cities such as Santa Cruz, San Diego, Los Angeles, Huntington Beach, Pasadena, Carson and Davis, all have passed ordinances banning smoking on city and county beaches and in parks.

Meanwhile, a ban on smoking and vaping on beaches in New Jersey, with a $250 fine, took effect this year.

There was no organized opposition to the bills this year. But not everyone is happy with them.

Scott Saint Blaze, a Los Angeles surfer, bartender and veteran who led efforts in recent years to pass the smoking ban, said Thursday he is disappointed that Levine and Glazer watered down the bills.

The measures contain exceptions for smoking “used in connection with the good faith practice of a religious belief or ceremony,” a loophole requested by Native American groups. And the smoking ban does not apply to people smoking on “paved roadways or parking facilities” at state beaches or parks.

“There are so many gaping loopholes,” said Saint Blaze. “They pull more teeth out of a smoking ban that’s already flimsy.”

According to data compiled by the California Coastal Commission, which sponsors the annual cleanup, cigarette butts are the most numerous pieces of litter that volunteers find every year during the event.

Since 1989, when detailed records first began, 7.5 million cigarette butts have been collected during the annual cleanup in California, making up 37 percent of all the trash.

Food wrappers and containers, at 11 percent, are a distant second, followed by caps and lids at 9 percent, plastic and paper bags at 7 percent, and cutlery, cups and plates at 5 percent.

“Cigarette butts are a significant problem on our beaches,” said Eben Schwartz, marine debris coordinator for the Coastal Commission in San Francisco. “They are incredibly toxic and harmful when they get into the water. Studies have shown that signs on beaches have reduced the number of cigarette butts on those beaches, even without enforcement.”

After Santa Monica passed a smoking ban on its city beaches in 2009, the number of cigarette butts picked up on the beaches declined by 59 percent in the following three years, Schwartz said.

Last year, 71,756 people turned out in 55 of California’s 58 counties and collected 819,323 pounds of debris from beaches, rivers, creeks, lakes and bays. Of that, 59,969 pounds were recycled. The overall total was well below the record of 1.3 million pounds collected in 2014, part of a steady decline in recent years.

That drop, Schwartz said, is due to a number of things. They include a statewide ban on plastic grocery bags signed into law in 2014 and tougher regulations by state and federal officials requiring cities to reduce litter by catching it in storm drains and by other methods.

Every year in the annual cleanup, volunteers — who come from community groups, scout troops, corporate volunteer programs and families — work in nearly every California county. This year, there are more than 1,000 locations, and only three counties — Sutter, Merced and Trinity — do not have an organized cleanup.

Volunteers are asked to bring gloves and a bucket or bag. Every year, they find some odd things among the trash. In recent years, volunteers in Marin County found a painting of a marsh in a marsh. In Los Angeles County, they found a Coke can from 1963 along a stream. And a volunteer found an old book on a beach in Monterey County with two tickets tucked inside to an inaugural reception to President Warren G. Harding, who was elected in 1920.

“It sounds weird to say this, but it’s a lot of fun,” said Schwartz. “It’s fun to clean up trash.”

The best part of the event, he said, is the “sense of power” volunteers leave with.

“They show up to a place that is dirty, and in only three hours, they restore it,” Schwartz said. “They clean it. Their work has year-round repercussions.”

He added, “It’s a powerful opportunity for people to give back to these places that we all love.”