From Calif. to Denver: Ozone woes become regional Ozone pollution — once seen as mainly an urban problem — is spreading across the interior West from rural Wyoming to suburban Phoenix. Levels of the corrosive gas that can impair breathing have exceeded federal health standards in Wyoming, New Mexico and Colorado. Four Arizona counties and two in Utah also are likely to exceed a new, tighter federal standard, according to the Environmental Protection Agency. "It's a new ballgame in the West," said Mary Uhl, New Mexico's air quality director. "We've got to do something, and we've got to do it now." In Wyoming, ozone levels in rural areas are "creeping up," said David Finley, state air quality division administrator. "We need to keep our eye on this." The emerging pollution problem is leading to tighter controls on oil and gas operations and raising questions about how much development the West can sustain....