Living in the middle of a natural gas boom can be pretty unsettling. The area around the town of Silt, Colo., used to be the kind of sleepy rural place where the tweet of birds was the most you would hear. Now it's hard to make out the birds because of the rumbling of natural gas drilling rigs.
The land here is steep cliffs and valleys. But bare splotches of earth called well pads are all over the place.
"That's the one I'm worried about because it just went in," says Tim Ray.
Michelle Salvini (left) and Terri DiCarlo take a break from work outside the Cornerstone Care clinic in Burgettstown, Pa. Mysterious fumes have repeatedly sickened clinic staffers, forcing them to evacuate the building several times.