Volunteers scraped up 50 pounds of gum from under the seats of the Red Rocks Amphitheatre last year.

"The Marcus Eriksonbenches look so amazing and clean!!!" the non-profit group, Friends of Red Rock wrote in a Facebook post.

Red Rocks Amphitheatre is a naturally formed outdoor venue just fifteen miles west of Denver, Colorado. It's recognized for its "star-studded concert roster, natural acoustics and ambience, as well as its awe-inspiring hiking and biking trails," according to the venue's website.

The group works to “preserve the magic of Red Rocks," and for the past three years has been removing the gum from under the benches at the park.

Volunteers spend three hours on the last Saturday of every month helping rangers clean up the trails, pick up trash, and scrape up gum, KDVR reported.

“Gum is not even permitted inside the amphitheater, but how do you prevent that? People have it in their purses, in their pockets,” Pia Valeriana, a volunteer with the group told KDVR. “We hope that people will chew responsibly and put it in a paper and not to stick it under the seats.”

Valeriana told the outlet that volunteers even find gum, which is prohibited in the venue, during the winter months when there's no venues.

“It’s disrespectful of this natural wonder we want to preserve in its most pristine way,” Valeriana said. “We just want people to be aware, and don’t take this place for granted. This is a unique place.”

Red Rocks Amphitheater

The Amphitheater "is a geological phenomenon – the only naturally-occurring, acoustically perfect amphitheatre in the world," according to the venue's website.

It's situated on the traditional territory of the Ute, Cheyenne and Arapahoe Peoples. Red Rocks Park is a "unique transitional zone where the Great Plains meet the Rocky Mountains," and is located 6,450 feet above sea level.

It's recognized for its "star-studded concert roster, natural acoustics and ambience, as well as its awe-inspiring hiking and biking trails."

Performers including U2, Johnny Cash, Jimi Hendrix, Diana Ross, Bruce Springsteen, Stevie Wonder, Bob Dylan, Dave Matthews Band, Mumford & Sons, Sting, and The Beatles have all taken the stage at the unique venue.