Joshua Tree National Park is “as pristine as any site in the California desert today or ever will be in the future,” the State Water Resources Control Board has said. Noting its proximity to Los Angeles, the National Park Service once touted how “for people who are subjected to automobile congestion, air pollution and disappearing open space, (the park) offers rest and relaxation, fresh air, clear skies, outdoor recreation, solitude and contemplation.”

But last year, Joshua Tree National Park failed to meet the Environmental Protection Agency’s ozone standards, with many of its sites charting smog levels far higher than the 75 parts per billion standard established by the federal government in 2008. And Joshua Tree isn’t alone. From Yosemite’s Turtleback Dome to Sequoia and Kings Canyon’s Ash Mountain and Lower Kaweah, several national park sites have failed to meet federal smog standards.

?Though the amount of ground-level smog has decreased at an accelerating pace over the past four decades, the EPA’s standards keep getting tougher, with the agency reconsidering its mandates at least every five years under current law. The last regulatory revisions, established in 2008, were so stringent that several national park sites – as well as myriad cities and towns across America – fail to meet them.

Instead of creating more realistic goals or waiting for states to reach more uniform compliance with current regulations, the EPA is now finalizing even more adamantine smog standards to mandate ozone levels somewhere between 60 and 70 ppb.

At those levels, the number of noncompliant national park sites will roughly double, and even immaculate places like the Mojave Desert and Colorado’s Longs Peak could land on the naughty list. Thousands of cities and counties could also find themselves in violation, forced to impose stringent measures that hinder economic growth and cost billions of dollars. Overall, the National Association of Manufacturers has said the smog rules “could be the most expensive regulation in history.”

The EPA claims lower smog levels would yield significant health gains. Then again, it’s increasingly clear that the EPA is cherry-picking its science, giving undue consideration to studies that support lower ozone standards while ignoring research that doesn’t match the agency’s political agenda.

The EPA has given great import to studies with small sample sizes, poor controls or unlikely scenarios, according to a June 17 letter to the agency written by 23 physicians in Congress.

For instance, the EPA reanalyzed one study on exercise and ozone, drawing the opposite conclusion as its author, William C. Adams of UC Davis. He later told the EPA that it had “misinterpreted the statistics contained in my published, peer-reviewed paper.”

The EPA has also leaned heavily on decades-old findings, even though new studies may present different, more relevant perspectives. And in other instances, the agency has altogether refused to reveal what data it has used to reach its conclusions about appropriate pollutant levels.

In other words, junk science can enjoy its heyday, as long as its conclusions are politically convenient for an overzealous EPA.

The reality is that Americans want clean air and economic opportunity – and with few exceptions, they currently enjoy both. Ignoring that, at enormous economic expense, the EPA is pursuing standards that even the federal government can’t meet on national park land.

Jillian Melchior is an energy fellow for Independent Women’s Forum. The nonprofit organization relies on the support of donors, including some industries or individuals who may be affected by the ozone rules.