The hardest hikes in Colorado, by the numbers
Of the 577 trails in Colorado in our dataset, 162 (28 percent) rate strenuous or very strenuous on the gain-and-distance scale we use and run 3 to 30 miles with at least 1,500 ft of climb; these are the 25 with the highest rating.
Chicago Basin 14er Grand Slam leads with 12,167 ft of gain over 28.9 miles, 421 ft per mile, with a steepest pitch of 68 percent.
Across the 25, gain runs from 3,784 to 12,167 ft and distance from 12.5 miles to 28.9 miles; the median gain is 4,886 ft and the median distance 17.3 miles.
9 of the 25 are loop routes; the rest are out-and-back (8) or point-to-point (8).
How this list is ranked
Rating = the square root of 2 x elevation gain (ft) x distance (miles), the gain-and-distance formula Shenandoah National Park publishes for its own trails. Bands: under 50 easiest, 50 to 100 moderate, 100 to 150 moderately strenuous, 150 to 200 strenuous, 200 and over very strenuous.
This list: band strenuous (150 to 200) or very strenuous (200 and over), 3 to 30 miles, at least 1,500 ft of gain, ordered by rating desc, gain per mile desc, capped at 25. The rating column is computed from the miles and gain printed in the same row, the numbers each trail page uses, so every row can be checked from the row itself. The rating says nothing about exposure, scrambling, altitude or conditions.
Only trails with a full page count, so "Colorado" here means the 577 trails in Colorado in our dataset, not every trail in Colorado.
Each trail page shows the full elevation profile behind these numbers and the same data drawn as a topographic print, made to order. Start with Chicago Basin 14er Grand Slam.
Hardest hikes elsewhere.
The same ranking for other states in our dataset.