Lewis and Clark Pass

Overview

Lewis and Clark Pass is a Category 1 climb in the US, running 5.7 km from a start elevation of 1460 m to a summit of 1955 m. That gives a net elevation gain of 495 m at an average gradient of 8.63%, putting it firmly in the range where the climb demands respect from the first pedal stroke. There is no long false-flat run-in to hide behind here; the average alone marks it as a sustained effort.

The total ascent of 581 m sits 86 m above the net gain of 495 m, and that gap tells you the profile is not a clean, single-direction ramp. Those extra 86 m come from dips and rollers along the way, meaning you pay for elevation you then give back before climbing it again. Undulation like this raises the real cost of the climb above what the net figure suggests, and it makes rhythm harder to hold.

How the Gradient Unfolds

The 8.63% average is a blended figure, and blending hides the sharp end. With a maximum gradient of 24.65%, there are pitches far steeper than the average implies, offset by shallower or briefly descending sections that pull the mean back down. Do not treat the average as your target grade — plan for spikes.

• Flatter or recovery sections where the road eases and briefly gives back elevation, contributing to the 86 m of extra ascent
• Repeated short climbs stacked between those dips, so the effort resets rather than settling into one steady grind
• The steepest ramp near 24.65%, where you will need your lowest gear and a deliberate shift in effort

Pacing Notes

On a smooth climb, even-effort and even-speed pacing nearly converge. On an undulating climb like this one, they diverge sharply. Chasing an even speed forces you to spike your power on every steep ramp, and those repeated surges above your sustainable power output drain you well before the summit. Ride to even effort instead: let your speed fall on the steep pitches and carry momentum through the flatter sections. Before the ride, pin down your numbers with the FTP estimator so you have a ceiling to pace against on the 24.65% ramp rather than guessing.

Gearing

The steepest gradient governs your gearing, and at 24.65% that means going low. Run a compact (34-tooth inner ring) or a sub-compact chainset, paired with a wide-range cassette such as 34×32 or 34×34. A 34×34 gives you the spinning room to keep cadence up on the steepest ramp instead of grinding to a stall. Check your setup before the ride — confirm the cassette and derailleur can actually handle the largest sprocket, because discovering you are over-geared on a 24.65% pitch is not a mistake you can fix mid-climb.

Summary

• Length: 5.7 km
• Average gradient: 8.63%
• Maximum gradient: 24.65%
• Net elevation gain: 495 m
• Total ascent: 581 m
• Category: 1

Lewis and Clark Pass rewards riders who read the profile rather than the average. Gear low, pace by effort through the 86 m of undulation, and save something for the steep ramp near the top.