Ever since the days of Julius Caesar, "crossing the Rubicon" has signified the making of a commitment from which there is no backing down. How remarkably apt, then, that the Rubicon Trail requires a similar kind of dedication along with almost military levels of preparation. And considering Jeep, a marque with close associations to the Rubicon Trail, is now owned by an Italian company (Fiat), plus the use of a metaphor now linked to metalworking, old Julius was far more prophetic than he could ever have known.

Jump forward a couple of millennia to the Sierra Nevadas in California in 1887. Gold had already been discovered (hence the El Dorado Forest), pioneers like John McKinney were putting down roots, and the West was becoming less wild -- as evidenced by water from Rubicon Springs being bottled and sold to the health-conscious. The trail that led there from Wentworth Springs was declared a public highway, making it illegal to close it down. It's now an unmaintained county right of way known as the Rubicon/McKinney Road that runs between Georgetown and Lake Tahoe.

This area has been used for recreation for more than 125 years. Yep, there's camping and hiking and fishing, but motorized transport has played a large part. The first motor car entered Rubicon Springs in 1908 (a Mitchell, built in Wisconsin). In 1953, a group of Jeep owners covered the trail, starting a tradition known as the Jeepers Jamboree that takes place every year and has grown from 55 vehicles to around 750.

Between then and now, a lot of the trail has been paved, but there are still plenty of difficult sections to negotiate. It takes two days to complete all 22 miles; when there's a mountain on one side and a sheer drop on the other, sometimes it's good for Jeepers to be creepers. The route is two-way, but most users travel west to east, toward Lake Tahoe.

This is the oldest 4x4 trail in the United States and has been recognized for its toughness, for the demands it makes on axle articulation and suspension compression, on approach and departure angles, breakover points, and wading ability. That's why companies including Jeep and Toyota test upcoming four-wheel-drive vehicles on the Rubicon Trail. If an off-roader can tackle the Rubicon, it can pretty much tackle anything else. And, yes, with the right set of tires and appropriate pressures, a bone-stock Jeep Wrangler can cross the Rubicon.

The trail also attracted more extreme specialist vehicles. "Rock crawling was really invented here," says John Arenz, vice president of the Rubicon Trail Foundation. Things got a little intense in the 1980s and '90s. "Now, it's back to where it was. A more friendly place to be, more of a family trail."

That kind of sport, though, was bound to bring the wrong kind of attention. "Environmentalists see the Rubicon as the brass ring," Arenz explains. They have a three-pronged attack: sanitation, erosion, and oil spill. The Rubicon Trail Foundation has a three-fold solution: kits that mop up any oil, erosion control features such as rolling dips and energy dissipators, and WAG. That's waste-absorbent gel.

The foundation also organizes work teams to keep the route open all year 'round. They will remove any trees that have come down during the winter and make sure the erosion control features are intact. Officially, this route is unmaintained, but there are a few groups that provide some TLC. With around 70,000 visitors a year, El Dorado County also recognizes the trail's economic benefits and is seeking protection for it under the Historic Objects Act.

The Rubicon Trail is one of those must-do destinations for anyone who gets even the slightest thrill from kissing the pavement goodbye and wandering into the wild. Don't forget the water and the WAG.