A volunteer picks up trash at a previous Flagstaff Trash Bash.

It was a perfectly nice day on Flagstaff Mountain until local climber Willie Mein was hit by a cigarette butt.

"I was at Cloudshadow with Terry Murphy and Andy Donson, bouldering in the corridor on the backside, which was full of broken glass, cigarette butts and trash," Mein said.

If you go

What: Flagstaff Trash Bash

When: 5 p.m. Wednesday

Where: Meet at Flagstaff summit parking lot

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"Terry sliced his hand on a piece of glass, and I'm back there with my shirt off, and I get hit with a burning cigarette butt from above."

The upside of the incident is that immediately afterward, Mein organized the first Flagstaff Trash Bash.

Mein called Boulder Open Space and Mountain Parks to make sure it was OK, and a mere nine days after OSMP approved it and offered food for the volunteers, he organized an event with 70 volunteers.

That was 10 years ago; this year's Bash starts at 5 p.m. Wednesday at the summit. Mein is hoping for 150 volunteers. A barbecue follows the two-hour clean-up. (And Mein says there will be plenty of anti-bacterial soap.)

The first year, the trash was over the top.

"Anything bigger than a quarter, we didn't even bother to pick up, because there was so much of it," Mein said.

Over the years, volunteers have picked up some odd items, said Murphy, president of the Flatirons Climbing Council, such as the skeletal remains of a car, a porcelain toilet and the remains of the old Flagstaff star that had been vandalized and dragged off.

Flagstaff is much cleaner nowadays.

"The total amount of debris has diminished, and we're not finding the exotic items nearly as often, either," Murphy said.

Also, the rock is cleaner. OSMP loans the volunteers Shop-Vacs for vacuuming up shattered glass off the tops of rocks and along the bases.

But there's still plenty to clean up. Mein scouts the mountain ahead of time so he knows where to send volunteers. And it changes -- he recently visited an area on Flagstaff he'd never been to and found a bunch of trash.

Murphy said the clean-up affects hikers and trail runners, too, and the volunteer turnout reflects that.

"It's a pretty well-rounded group up there," he said.

Mein said he hopes that people start picking up after others every time they climb or run the trails, not just during the Bash. It's about instilling a sense of stewardship.

"It's not just dealing with the trash -- it's educating people that it's not OK to flick your cigarette butt or leave your bottle," Mein said.

"When you go to a place that's already trashed, people don't feel that leaving a cigarette butt or a can is a big deal. But it's really different if you go somewhere that's clean, your trash stands out."

"We hope people realize it's pretty pristine up there."