With its white-knuckle mountain drives and haul-it-yourself ranching treks on the eastern plains, Colorado has long been a truck-friendly state. More than 60 percent of automobiles sold in Colorado are pickups and sport-utility vehicles. In fact, we’re the only state to have inspired a truck name (the Chevy Colorado), and three SUVs (the Chrysler Aspen, Dodge Durango, and Chevy Avalanche). Colorado loves its 4WDs.

But, apparently, our love is dimming. In 2007, Coloradans bought almost 100,000 light trucks (including pickups, SUVs, and vans). That was less than a 1 percent increase over 2006—and this year, light truck sales are expected to fall 4.4 percent as the economy drops off and gas prices continue to rise. If analysts are right about $4 gas, filling up your Ford F-150—the best-selling Colorado auto—will set you back a C-note.

Meanwhile, Congress and state governments are requiring tighter fuel-efficiency standards in an effort to combat global warming. In December, Congress passed a law raising fleet-wide fuel-efficiency benchmarks to 35 miles per gallon by 2020. SUVs and pickups are way off that mark: Many average less than 20 miles a gallon. Closer to home, Governor Bill Ritter has proposed stricter emissions standards for new cars, modeled on the laws recently passed by California and 15 other states.

All this means that automakers will have to build more efficient engines, sell more hybrid vehicles, and use more lightweight metal. Vehicles will be sleeker, lighter, more environmentally friendly, and more expensive—a few hundred bucks to $1,000 more than their more conventional brethren.

But don’t expect Colorado’s love affair with trucks to disappear. Unlike Miamians driving Hummers, Coloradans’ egos aren’t buying gas-guzzlers—often the only way to get to our forests, mountains, and rivers through ever-changing weather is with 4WD. If our SUVs get a little more expensive, so be it—it’s a minor cost to save our beloved destinations from global warming’s wrath.