Alto de Cienaga

Overview

Alto de Cienaga is a genuine hors catégorie (HC) monster — the hardest classification on the scale, sitting above categories 1 through 4. It stretches 22.1 km and averages 6.58%, hauling you from a valley floor at 748 m all the way to a summit at 2199 m. That works out to 1451 m of net elevation gain, though the road actually stacks up 1486 m of total ascent once you account for the small dips and recoveries along the way. This is a climb measured in fractions of an hour, not minutes: pace, patience, and gearing decide your day long before the summit does.

How the Gradient Unfolds

The headline number — 6.58% average — is honest but tells only part of the story. Over 22.1 km, a mean gradient like that hides real variety. The 35 m gap between the 1451 m net gain and the 1486 m of total ascent confirms the profile isn't a clean, monotonic ramp: there are brief false flats and shallow descents where the road gives a little back before demanding it again. The sting is the 37.9% maximum pitch, a wall-steep ramp that will spike your effort far beyond anything the average suggests. Expect the climb to alternate between sustained mid-single-digit grades and sharp kicks, so read the road ahead and never let a steep section catch you in the wrong gear.

Pacing Notes

On a climb this long, discipline beats bravado. Anchor your effort to your FTP and aim to hold a sustainable percentage of it for the full 22.1 km rather than surging on the flatter stretches. A good rule of thumb: settle into a rhythm you could theoretically hold for well over an hour, because at 6.58% average across 22.1 km, that's roughly what you're facing. Save a little in reserve for the 37.9% ramp — that pitch alone can blow a pacing plan if you hit it already redlined. If you don't know your threshold, run the numbers first with the FTP estimator so your target power is grounded in data, not guesswork.

Gearing

Do not under-gear this one. With a sustained 6.58% average, extended time above 2199 m of altitude at the top, and a 37.9% maximum pitch, you want spinnable ratios. A compact 34-tooth inner chainring paired with a wide-range cassette is the baseline. A 34×32 will get most fit riders up in reasonable comfort, but given the length and that brutal max gradient, a 34×34 is the smarter insurance — the extra tooth turns the steepest ramps from a grind into a survivable cadence. If your bike accepts it, err toward the easier option; you will never regret a spare gear at 2199 m.

Summary

Alto de Cienaga is a complete HC test: 22.1 km of climbing, a 6.58% average punctuated by a 37.9% maximum, and 1451 m of net gain from base to summit. Gear low, pace to your threshold, and respect the distance — the mountain rewards riders who plan.

Length: 22.1 km
Average gradient: 6.58%
Max gradient: 37.9%
Start: 748 m
Summit: 2199 m
Net gain: 1451 m
Total ascent: 1486 m
Category: HC