Sylvan Pass

Overview

Sylvan Pass sits inside Yellowstone National Park, Wyoming, and earns its Category 2 rating through sheer gradient volatility. The numbers tell a mixed story: a 5.78% average gradient across 6.1 km sounds manageable, but a maximum gradient of 19.97% means significant portions of the road depart sharply from that average. Total ascent of 819 m on a road that only nets 351 m of elevation gain confirms it — the profile is broken up by dips and surges, not a steady ramp.

How the Gradient Unfolds

Starting at 2,274 m, you're already at altitude before you turn a pedal. The climb finishes at 2,625 m, a net gain of 351 m, but the 819 m of total ascent tells the real story: the road gives back meaningful elevation in at least one significant descent mid-climb before pitching upward again.

What to Expect Section by Section

• Lower slopes: The opening kilometres tend to lull riders into a false sense of pace. The average gradient of 5.78% is workable, but banking time here and overcooking your effort sets up a painful reckoning on the steep ramps above.
• The steep ramps: With a maximum gradient of 19.97% — effectively a 1-in-5 pitch — there are moments where gearing becomes the deciding factor. These aren't prolonged walls, but they arrive sharply and require immediate power output or a gear you've already spun down to.
• The descent interruption: The gap between net gain (351 m) and total ascent (819 m) is large enough to account for a descent of several hundred metres. Use the downhill to recover breathing and heart rate, but don't coast through it mentally — the road climbs again on the far side.

Pacing Notes

The altitude baseline of 2,274 m at the start is a serious physiological factor. Even riders well-conditioned at sea level will notice reduced oxygen availability. Your FTP effectively drops at elevation — if you haven't tested or estimated your altitude-adjusted threshold, the FTP estimator can provide a starting point before you target a power ceiling for this climb.

Given the mid-climb descent, resist treating Sylvan Pass as a single sustained effort. Structure it more like two or three separate climbs:

1. First ascent segment — Hold back. Ride at 75–80% of your altitude-adjusted threshold. The ramps haven't arrived yet.
2. Descent — Recover, but keep cadence turning over. Don't let legs stiffen.
3. Final push to 2,625 m — You can extend effort here, but the near-20% sections will force you off the big ring regardless of fitness. Stay seated on the steep ramps if possible; standing burns matches faster at this altitude.

Gearing Recommendations

For most riders, a compact chainset (50/34 or 48/32) paired with an 11-32 or 11-34 cassette is appropriate. A 19.97% gradient is steep enough that riders on a standard 53/39 setup will either grind to a near stop or be forced to stand and sprint — neither is efficient over a Category 2 effort. If you're unsure how your gearing maps to gradient demands, the gear ratio glossary covers the relevant calculations.

Summary

Sylvan Pass is not a steady grind. It's a technically demanding Category 2 climb that combines altitude stress, mid-route elevation loss, and a maximum gradient close to 20%. Respect the altitude, save something for the upper ramps, and have the gearing to manage the sharp pitches without blowing up.