This may be the steepest road in Boulder County. I’m sure there are steeper ‘roads’, but this is a well graded dirt road which is open year-round. Additionally it is a through road and is also known as County Highway 89.
Length: 1.0 miles (1.6 km)
Average Grade: 14.2%
Maximum Grade: 18.2%
Vertical Gain: 754 ft (230m)
Summit: 8286 ft (2525m)
Tour de France Category: N/A
Tour de France analogue: Only the Monte Zoncolan Featured in the Giro d’Italia has prolonged sections this steep (a mile of the climb averages 14%, although the Zoncolan is a whopping 6 miles long at 12% average). Also, Stage 4 of the 2010 Vuelta a España featured a tough final kilometer with 0.5k at 15% grade. (Note, the Vuelta does not categorize finishing climbs)
Over the years I have spent most of my cyclocross training on my road bike, or indoors due to bad weather. This year I have been getting out more on my cross bike and have finally ridden some of the great dirt climbs of Boulder County. Lickskillet road is too steep, and frequently too loose to be possible to climb on a road bike, although in very good conditions it may be possible.
The climb ascends unceremoniously from Lefthand Canyon to the town of Gold Hill. 750 vertical feet. No switchbacks. One mile. I don’t really have much more to say about this one except it is rumored to be the steepest county road in the United States. I’d recommend a mountain bike, or cyclocross bike with easy gearing, as I was struggling in my 34-27 to ascend the upper sections which include 1/4 mile at 18.2% grade.
In fact, the climb is so steep, the math begins to get complicated! Percent grade is defined as ‘rise over run’, or horzontal distance divided by vertical distance. Keep in mind that a GPS measures the distance traveled; the hypotenuse of the triangle, not the base. For almost all grades encountered on a road, the difference in the calculations is minuscule.
Take for example riding 5280 feet and gaining 528 feet. A Simple Grade Calculator would give you an even 10% grade. However, the actual horizontal distance you traveled was 5258 feet, yielding a corrected percent grade of 10.04%. The steepest section of Lickskillet climbs 241 feet over 1320 feet (1/4 mile). The simple calculation gives 18.25% grade, but by the more accurate calculation comes to 18.56%.
So I guess what I really mean to say that you can put away that trigonometry textbook, since the pain of ascending lickskillet road is enough, and really no road is steep enough to justify anything but a simple grade calculator.