Thompson Pass

Thompson Pass cycling climb profile

Thompson Pass is a category 2 climb in the US that asks for discipline more than drama. On paper, the core numbers are clear: 12.6 km in length, 645 m of net elevation gain, and an average gradient of 5.12% from a start elevation of 167 m to a summit elevation of 812 m.

That makes it long enough to punish poor pacing, but not so steep that the climb is defined by repeated survival efforts. The maximum gradient is 9.19%, which means there are sharper ramps in the road, but the overall profile points toward a sustained aerobic climb rather than a stop-start wall. The key is not whether you can handle the steepest pitch once. It is whether you can keep the effort under control before and after it.

How the gradient rides

With an average just over 5%, Thompson Pass should feel like a climb where momentum matters. Most riders will be able to stay seated for long stretches, settle into a rhythm, and ride close to threshold without needing repeated out-of-saddle resets. The danger is that a moderate average can make the opening feel too manageable. If you ride the first part like a tempo drag and then meet the steeper sections already above your sustainable range, the final kilometres become much more expensive.

Because the listed maximum is 9.19%, gearing should be chosen for the steepest moments, not the average. A rider who gears only for 5.12% risks being forced into low-cadence grinding when the road pitches up. That matters because grinding above threshold increases muscular load and can turn a controlled climb into a slow fade.

Pacing and gearing notes

Treat Thompson Pass as a steady-state effort with a few sharper interruptions.

• Start below target effort, especially if riding by FTP or power.
• Let cadence stay natural on the 5% terrain, but keep a gear available for the ramps near 9%.
• Avoid chasing speed early. On a climb this long, small overages compound quickly.
• If riding without power, use breathing as the governor: controlled and repeatable early, harder only once the summit is clearly within reach.

For a strong endurance rider, the best execution is a negative split in effort rather than speed. Keep the first half boring, absorb the steeper sections without spiking too hard, then lift the pressure once the climb has already taken its main tax. Thompson Pass is not won by one violent acceleration. It is ridden well by keeping the middle of the climb efficient enough that the summit push is still available.