They packed the train stations, rode busses from miles away. They rode bikes and pushed strollers up Capitol Hill. They came from all walks of life—doctors and dads, hipsters and grandmothers, and the skiers and snowboarders who spend their days in the clean air above Salt Lake City’s inversion, but most of whom have to descend back into it every night to get home. Some 5,000 people marched on the Utah State Capitol on last Saturday, January 25. It was the largest air pollution protest in Utah, and by some reports, the largest in American history. Standing next to the advocacy groups including Utah Physicians for a Healthy Environment (UPHE), the Sierra Club, and Clean Air Utah, were a loose confederation of professional skiers, snowboarders, climbers, and mountain bikers who love living and training near the Wasatch Range, but hate descending into a brown cloud of pollution during Utah’s inversion cycles.

“[The turnout] was obviously amazing. It was way beyond our expectations, or at least mine,” says Amanda Batty, a professional mountain biker and passionate skier who helped found the group Athletes for Clean Air, a non-profit group fighting for clean air in Utah. “Even cooler than the total turnout was the amount of people who chose alternative transportation to get to the rally.”

Northern Utah cities consistently rank as the most toxic in North America for air quality. During high pressure days, especially in the winter, pollutants from the roughly 2 million people living along the Wasatch Front get trapped in the valley, and build until the next storm front. UPHE estimates that between 1-2,000 people each year die prematurely because of the air quality in Utah.

Athletes for Clean Air is currently a small voice in the chorus for change. For now, the group is only comprised of outdoor sports athletes, but Batty sees that expanding soon. “We’ve reached out to a few different athletes from various organizations, and have gotten quite a response,” she says. “The response level from athletes from all sports disciplines has been absolutely amazing, and it’s really reaffirming that what we’re doing matters.”