Lookout Mountain is the climb in Denver.
Length: 4.55 miles (7.32km)
Average Grade: 5.4%
Maximum Grade: 6.8%
Vertical Gain: 1254 ft (382m)
Summit: 7700 ft (2214m)
Tour de France Category: 2
Tour de France analogue:
Col du Noyer – Final climb, Stage 10, 2010 TdF
This is an incredibly popular climb starting in Golden. The climb is measured from the tall stone pillars at the gates of the park, and ends at the turnoff to the overlook at the top. This climb is incredibly popular with tourists and cyclists. Traffic is minimal on this road.
I think the climb is so popular because it isn’t terribly hard. With an average grade of 5.4%, most recreational cyclists can ascend it, even without a triple or compact crank. Yet it still provides a challenge, a yardstick (ascent time), a nice ride near the city with little traffic, and enough of a challenge.
I divide the climb into thirds. The first third heads northward from the pillars to the first switchbacks. This section climbs steadily with great views of Golden, and North and South Table Mountain to the east. The second third heads southward past the “M” (for Colorado School of Mines) and the grade eases somewhat, with a few ‘flat’ sections.
The final third is from the parking lot a the saddle with views to the west. The grade past the saddle is the steepest, maxing out at 6.8% for 1/2 miles, and ascending the three tightest switchbacks. The road climbs steadily passing a few nice overlooks of the entire Denver metro area, and then has a quick flat section before the final 200 yards to the top. You can make a nice ~20 mile loop by continuing to Highway 40 / I-70 Frontage Road and dropping back into Golden.