She was counting cigarette butts on sidewalks lining the block bounded by Railroad Avenue, Holly Street, Cornwall Avenue and Magnolia Street, with side trips to The Royal, Starbucks Coffee and Downtown Johnny's Restaurant & Nightclub.

Walker conducted her tally on a Monday morning, after a weekend and before downtown cleanup crews got busy. Care to guess how butts many she found?

If you guessed 3,990, you win.

"I was actually surprised," Walker said. "That's a lot."

Indeed it is. If each of those butts were a standard 1-inch-long filter and were laid end-to-end, they would reach nearly that full block of Railroad - from the Little Cheerful Café all the way to Sandy & Vale's Shoe Repair.

Tossing a cigarette butt on the ground is littering, subject to a $50 fine. Yet many smokers think they're doing the right thing, the safe thing, by stomping their butt out on the ground or tossing it into a gutter or drain.

Or maybe they just don't care. Either way, a lot of people do it, especially since new laws forced smokers to light up outside.

Cigarette litter is plentiful. It's also long-lasting, because most filters are made of durable plastic.

"It's just become a major burden on our maintenance crew," said Walker, executive director of Downtown Renaissance Network, the business organization that cleans and beautifies downtown.

"You think one little cigarette, what's the big deal," she said, "but 3,990 in a block, now that's a big deal."

That's why the organization is staging a month-long campaign backed by Keep America Beautiful, a national nonprofit outfit that, among other things, fights litter.

Walker's July 14 count set the benchmark. She'll do another count by Aug. 18 to see if the campaign makes a difference.

According to Keep American Beautiful, the number of butts on the ground should drop by 54 percent, based on the average decline at participating communities last year.

The campaign includes having businesses hand out fliers and free pocket ashtrays, and installing cigarette receptacles on downtown sidewalks. The metal receptacles are tall, tubular and bolted to the ground.

In mid-August, Bellingham police on bicycles will focus one weekend on handing out friendly warnings and pocket ashtrays to people who leave cigarette litter on the ground.

Once the campaign ends, organizers will meet to decide what to do next. For now, Walkers hopes more people will realize that cigarette butts are harmful litter that need proper disposal.

"I hope it gets people to start thinking," she said.