Bette Midler
I've had several million aha! moments in my life, but one of my biggest didn't take place on a mountain peak at sunrise or onstage in front of a sold-out crowd; it was actually on top of a garbage heap.

I've always been drawn to activism. I marched in the 1960s, did sit-ins in the '70s, removed garbage from a highway I "adopted" in the '80s. By the '90s, I'd gathered a group of volunteers dedicated to cleaning up New York City. I'm from Hawaii, and when I moved to Manhattan, I was shocked by how filthy it was. So I started a foundation, the New York Restoration Project, with my own money, some funds I'd haggled, and a fabulous band of urban environmentalists. Every day, year-round, we tackled rundown community gardens, gum-sticky streets, and bottle-strewn alleyways.

One day in 1997, we were working on a park in northern Manhattan. We thought we had the city pretty well covered until one of the volunteers suggested we explore a different park on the other side of Manhattan, an area that had been closed for 30 years. "It's dangerous over there," a cop warned. We thanked him and set off.

As we entered this park, the signs of normal life—joggers, moms with strollers, businesspeople on lunch break—disappeared and were replaced by a surreal landscape: garbage so thick that we were soon walking on it and, in some places, so high that the only proof of a path was the tops of streetlamps poking through the waste. It was fantastical, bizarre, criminal. Squatters peered out at us from behind trees; entire ramshackle industries—pimps, drug dealers, chop shops—were operating.

As we continued on the junk path, we came upon a hillside under gigantic stone arches. These regal architectural masterpieces, evidence of the park's glamorous past, marked the place where the well-to-do came to see carriage races in the 19th century. Only now, instead of people and horses, there were thousands of old black tires piled 20 feet high, dumped for decades off the highway. They looked like an act of malice against the environment. Some of my friends began to cry.

That was my moment—gazing out over Tire Alley, as we dubbed it, atop ten feet of beer cans and diapers, I knew this wouldn't be just a part-time gig anymore. The city itself became my mission, through the good, the bad, and the dead body that we found in the rubble.

After two years of clawing and hauling, the unimaginable happened: We pulled the last tire out of the park. Highbridge is well on its way to being a stunning place now, rolling hillsides of green where people can safely go and enjoy the beautiful Harlem River views. The resolve that Tire Alley, in all its miserable glory, gave me and my team helped us to create a small revolution; since then we've cleaned up hundreds of acres of parkland in the city.

I've been changed by it, too. Who'd believe it—I'm actually pretty shy, but now I'll get on the phone and talk to anyone about funding. Also, I feel like a part of something, an entity that works on sheer will: We picked up one tire, then two tires, then 20,000 tires. It's remarkable to see such power.

After witnessing what's possible, I'm in this for good. As long as there are Tire Alleys, I'll be there with a pair of rubber gloves on, saying, "Get the trash off the streets and onto the stage, where it belongs!"

— As told to Justine van der Leun