Though remotely located in the mountains and canyons of northeastern Utah and northwestern Colorado, Dinosaur National Monument goes through days when the air quality is almost as bad as you'd find in major metropolitan areas.

The problem is tied, in part, to the rampant oil and gas development in the surrounding Uinta Basin of Utah. There, thousands of wells are generating air pollution levels that, in some parts of the basin, are on par with air quality in downtown Los Angeles. Some of that pollution drifts over to Dinosaur, where air sampling results show the national monument exceeded U.S. Environmental Protection Agency’s eight-hour National Ambient Air Quality Standards level for ozone pollutants some 26 days during the winter of 2012-13. 

While the EPA's eight-hour standard is 0.075 parts per million, at Dinosaur levels at times have reached nearly twice that, according to comments the National Parks Conservation Association presented Monday to the Utah Department of Environmental Quality in connection with proposed air quality rules for the Uinta Basin.

To gain better insights into the problem, the National Park Service has installed an air quality monitor near the monument's visitor center.

"Our system went in this winter, so any kind of results right now would really be preliminary because they don’t have much data," Dan Johnson, the park's chief of interpretation and visitor services, said Wednesday. “It’s been something that we’ve been concerned about, because we’ve seen the reports and the news reports from the past.”

How much of the problem is associated with the oil and gas exploration, he added, is difficult to say at this point. Other sources could be vehicle traffic or wood-burning emissions from fireplaces and woodstoves, said Mr. Johnson.