When gas prices soared above $4 per gallon last summer, a wave of Utahns converted their cars to compressed natural gas (CNG), which cost just 65 cents.

While price primarily fueled this shift, natural gas also burns cleaner and benefits the environment.

However, these autos have one drawback - CNG fuel pumps are somewhat scarce. Utah has 25 stations that provide the pressurized fuel to the public.

With that in mind, Gov. Jon Huntsman Jr. designated Interstate 15 through Utah an official natural gas corridor, hoping to encourage more CNG sites to sprout.

"Governor Huntsman set forth that vision so that people traveling through the state can fuel their vehicles with this cleaner-burning, homegrown natural resource," said spokeswoman Lisa Roskelley.

A fan of alternative fuel, Huntsman converted his Chevrolet Suburban to CNG three years ago, and also owns a hybrid.

Questar spokesman Darrin Shepherd said the natural gas provider purchased two large compressors to increase CNG availability along the Wasatch Front. The fuel currently costs 97 cents per gallon.

"We're swimming in natural gas, right here in our backyard," Shepherd added.

Converting to CNG requires installation of special fuel tanks in a vehicle's trunk.

"It's a trade-off," Shepherd said of relinquishing that storage space. "People have to decide the purpose of their vehicle and what makes sense."

About two years ago, John Mitton, of Saratoga Springs, made the switch and now owns three CNG vehicles.

Mitton refuels the cars overnight at home, using a special natural gas connection that cost him $9,000. Those hook-ups now run about $5,000.

"My number one criteria for getting involved was our reliance on foreign oil," Mitton said. "Would I rather buy my fuel from Questar or from people who want to kill us?"