Red Mountain Pass

Overview

Red Mountain Pass is a Category 2 climb in the US, measuring 7.3 km from base to summit. Over that distance it delivers a net elevation gain of 432 m, starting at 2,968 m and topping out at 3,400 m. That high summit elevation matters as much as the length: you are climbing in genuinely thin air, and your usable power at altitude will sit below what you produce at sea level.

The climb is not a clean, steady ramp. While the net gain is 432 m, the total ascent is 510 m — a difference of 78 m. That gap tells you the road undulates: it climbs, gives some of it back, then climbs again. Those extra 78 m of ascent are real work you have to pay for, so the effort is meaningfully harder than a simple point-to-point elevation difference would suggest.

How the Gradient Unfolds

The 5.88% average gradient is a blend, not a constant. With a maximum gradient of 12.78%, the road clearly stacks its difficulty into specific ramps while easing off elsewhere. Averages smooth over exactly the sections that break your rhythm, so treat the number as a planning tool, not a promise.

• Expect flatter or false-flat sections where the road gives back some of that 78 m of undulation — use these to recover, not to attack.
• Anticipate repeated short pitches rather than one continuous wall; the climb resets your legs several times.
• The steepest ramp bites at 12.78%, well above the average, and is where an over-eager early pace will cost you.

Pacing Notes

On an undulating climb like this, chase even effort, not even speed. Holding a constant km-split forces you to spike hard on the 12.78% ramps and coast on the flatter sections — the worst possible distribution of energy. Instead, anchor your ride to a target sustainable power output and let your speed rise and fall with the terrain.

Ease slightly on the steep pitches so you do not blow past threshold, and keep pressure on through the flatter recovery sections rather than soft-pedaling. If you do not know your numbers, run the FTP estimator first and set a ceiling you can hold for the full 7.3 km at altitude.

Gearing

The 12.78% maximum gradient governs your gearing choice. On a pitch that steep, at 3,400 m, you want low gears in reserve so you can spin rather than grind. Fit a compact or sub-compact chainset paired with a wide-range cassette — a 34×32 or 34×34 gives you the bailout ratio to keep cadence up on the steepest ramp. Check your setup before the ride; discovering you are over-geared halfway up is not the place to find out.

Summary

• Length: 7.3 km
• Average gradient: 5.88%
• Maximum gradient: 12.78%
• Net elevation gain: 432 m
• Total ascent: 510 m
• Category: 2

Red Mountain Pass rewards riders who respect its undulation and its altitude. Pace to power, gear for the steepest ramp, and the extra 78 m of ascent will feel like part of the plan rather than a nasty surprise.