They’re the big hills truckers love to hate. You’ve seen the ominous signs: “Caution!” “6% Grade,” “Runaway Truck Ramp Ahead,” etc. These steep sections of highway across mountain passes are scenic and even fun if you’re driving a four-wheeler, not so much if you’re piloting a loaded 18-wheeler. We researched numerous sources, from trucker and RV forums to DOT websites to find the most extreme mountain passes on the U.S. Interstate Highway system. We looked at variables such as length, grade, turns, traffic and weather issues. These are in no particular order, because on a bad day, any of these could top the list.
10. Fancy Gap (I-77, Virginia)
The Western U.S. has most of the more extreme interstate sections, but this stretch through Virginia’s Blue Ridge Mountains at the North Carolina border can be tough. The two southbound lanes descend almost 1,300 feet in about 6 miles. Now try that in the fog, with heavy truck traffic.
9. Cabbage Hill (I-84, Oregon)
This 7-mile run of I-84 35 miles west of La Grande, Ore., has a maximum grade of 6 percent. Passing through the spookily named Deadman Pass (3,631 feet), the area is subject to extreme weather conditions. Would you make the drive in the wintry conditions shown above?
8. Tejon Pass (I-5, California)
Cutting through the Tehachapi Mountains, this pass connects Southern California to the state’s growing Central Valley. The most treacherous part of the pass is known as the Grapevine, a 5 1/3-mile section with a 6 percent grade. In winter, it can be sunny in the valley, while there is a blizzard on the pass. And, like every other interstate in Southern California, heavy traffic is a given.
7. Monteagle Mountain (I-24, Tennessee)
This wild stretch of road about 40 miles west of Chattanooga was mentioned in Jerry Reed’s The Legend, which played during the opening credits of the classic 1977 film Smokey and the Bandit. The original section of highway was so dangerous, it had to be rebuilt in the 1980s to have the grade reduced and roadway widened. It’s still a challenge, especially for truckers.
6. Cajon Pass (I-15, California)
This pass between the San Bernardino Mountains and the San Gabriel Mountains has a tough 6-percent grade. Heavy traffic — and erratic drivers — can make this drive especially challenging for truckers and motorists alike.
5. Parley’s Canyon (I-80, Utah)
Westbound I-80 drops some 2,400 feet between this 7,016-foot summit in the Wasatch Mountains and Salt Lake City. The above video shows the eastbound journey, which is a beast itself.
4. Virgin River Gorge (I-15, Arizona)
One of the most challenging portions to build in the entire interstate system, this 9-mile route is a scenic wonder.
3. Vail Pass (I-70, Colorado)
The extreme grade of 7 percent is bad enough. Now try to negotiate that 10,666-foot pass on a ski weekend with thousands of motorists headed to/from the ski resort.
2. Snoqualmie Pass (I-90, Washington)
Located in central Washington’s Cascade Range, Snoqualmie Pass gets an average annual snowfall of more than 400 inches, and avalanches are common. For more than 60 years, a snowshed protected a portion of the highway from avalanches, but the state recently replaced that with a bridge. Still, closures and delays through the pass are common much of the year.
1. Eisenhower Pass (I-70, Colorado)
The Eisenhower Tunnel on I-70 about 60 miles west of Denver is the highest point (11,158 feet) on the U.S. Interstate Highway system. So approaches on both sides are steep. Westbound I-70 lanes have a maximum 6 percent grade.
(Slideshow photo credit: Ed Suominen)