[jyl]

Talk to a cabbie with a NG cab sometime. Issue is limited range and very (very!) few refueling stations. Like about 20 in Los Angeles County, many in inconvenient locations (feel like going to Compton at night to fill up?). I am not sure there are any in Portland.

The issue with fracking is not the rock. It is the groundwater aquifers - drinking water etc - and the fact that the oil & gas industry will not disclose the contents of their proprietary fracking fluids. When a community's groundwater is contaminated, it will be hard to trace it to a particular driller, and those drillers are organized to limit corporate liability. The cost of cleaning a town's water supply will be paid by taxpayers.