Last month, Glen Mays was having dinner at a rural mountaintop restaurant west of the city when a fellow diner collapsed with a heart attack. Mays, a college professor, leapt into action, clearing a space and giving the 60-ish woman CPR. For 35 minutes. "It was exhausting," he said. "I knew as soon as it happened that it would be 30 minutes or more until we got an ambulance up there." An ambulance racing up a nearby canyon from the outskirts of Denver finally reached the woman, and the EMTs got her heart beating again before rushing her to the hospital. Mays doesn't know if she survived. But he does know her chances of survival are significantly lower than had she been in Denver. "Incidents that are survivable in urban areas are often not in rural areas," said Mays, the chair of the department of health systems and policy at the Colorado School of Public Health.