Oil and gas usually take center stage when it comes to battles over mining in the West, but gravel has become the new enemy in Colorado’s St. Vrain Valley. Martin Marietta Materials, a company with operations throughout the U.S. and Canada, is planning to mine for gravel between Lyons and Longmont. The proposed 10-year operation would cause massive increases in air pollution, noise pollution, light pollution and traffic (trucks and trains), according to the nonprofit Save Our St. Vrain Valley. Calling on Boulder County Commissioners, the local group is demanding that Martin Marietta Materials go through the proper permitting process—and it hopes to derail the proposed mines.

“This company is not going to ruin my golden years,” says Richard Cargill, 75, a retired professor who has lived on Hygiene Road since 1995. “The air and noise pollution from this mine would be devastating.”

In response, Cargill and his neighbor Amanda Dumenigo formed Save Our St. Vrain Valley to advocate for local concerns. “A lot of cyclists, runners, and riders recreate throughout the St Vrain Valley,” says Dumenigo. “The reason why property owners invest and live here, visitors flock here, and athletes train here is the quality of life.”

Boulder County includes parts of Rocky Mountain National Park, which set an attendance record with 4.5 million visitors in 2016. And last year’s visitation number spiked an 8.68 percent increase over the previous annual record set in 2015, itself a 32 percent increase over 2014, and a 40 percent increase since 2012. The current permit allows for one truck every three minutes and three trains a day. Traffic to the park will be significantly impacted, as will the air quality and the pastoral views. Dumenigo worries that the experience of heading into the mountains will become vastly more industrial, potentially discouraging visitors.

“We fought Cemex and won,” says Cargill about forcing the cement plant just east of Lyons to comply with the Clean Air Act. “We’re going to fight again for what’s right.”

There’s also worry about dangerous crystalline silica dust.

“The St. Vrain Valley can be extremely windy, which makes it impossible to control fugitive dust events and airborne toxins from a mining operation,” says Dumenigo.

—Philip Armour