Extreme Travel

Why the tallest mountains in America are almost all the same height

Mount McKinley, also known as Alaska, is the highest peak in the United States.

Mount McKinley, also known as Alaska, is the highest peak in the United States.  (iStock)

The highest peak in the United States?

Easy: Mount McKinley in Alaska. The mountain is officially called "Denali" now, since the Department of Interior finally adopted the native Dena'ina name in 2015.

But Denali has only been part of the U.S. proper since 1959, when Alaska gained statehood. What was the highest peak in the United States before then? For decades no one was quite sure, because it's a surprisingly close call.

Being a frontiersman wasn’t an exact science. When the American West was being explored, the hard problem wasn't finding the high mountains—it was measuring them. Today, thanks to GPS and advanced mathematical modeling of the "geoid" (the underlying shape of the Earth), elevations can be measured to within a fraction of an inch. But a century ago, a surveyor's best option would be to climb a mountain, and then boil water or measure barometric pressure at the peak. So altitude measurements would be taken in inches (of mercury), not feet.

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Every tall mountain in America is basically the same height. As a result, mountaintop measurements could be wrong by hundreds of feet and that matters a lot in the continental United States. Due in part to coincidence and in part to a geologic process called the "glacial buzz saw," which limits how high mountains grow, all 30 of the highest peaks in the lower 48, from the Cascades of Washington to the Rockies of Colorado to the Sierras of California, are within just 500 feet of each other in height.

In Colorado, size matters. For example, Washington's Mount Rainier was measured at 14,408 feet in 1914, while California's Mount Whitney was originally believed to be 14,100 feet. This would make Colorado's Mount Elbert, at 14,433 feet, the highest mountain in America. But many Coloradans were annoyed that Elbert might even be the highest mountain in Colorado. Fans of nearby Mount Massive, which has a much more impressive silhouette, built a stone cairn atop its summit to retake the crown, only to have the manmade addition torn down by Elbert partisans.

Denali makes molehills out of mountains. Due to mismeasurements, many atlases and gazetteers listed Rainier as the nation's highest point well into the 20th century. Other sources placed it behind Whitney (correctly), Shasta (incorrectly), and several of the Rockies (both correctly and incorrectly). Its gradual demotion annoyed Alden J. Blethen, publisher of The Seattle Times, who wrote an angry front-page editorial accusing the other mountains of cheating by "starting" at such high-altitude bases.

Thanks to today's better surveying, the order is clear: Whitney, then three Colorado peaks, then Rainier. But Alaska statehood made the whole battle moot. Denali is over a mile higher than any of them.

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