Elevation for the tallest mountain in Idaho is actually higher than we thought

In Central Idaho, the Lost River mountain range towers over the landscape with Mount Borah as its apex. It’s easily Idaho’s tallest peak, roughly 400 feet taller than nearby Leatherman Peak, the state’s second-highest point.

Now new data shows Mount Borah is even taller than has long been thought — but experts said that may not be reflected on maps for years to come.

Mount Borah has long been considered 12,662 feet in elevation, despite reports that, following a 1983 earthquake, the peak rose by 1 foot. It was first determined as the state’s highest peak in the early 20th century, though Idaho Statesman articles from the time showed there was debate over when it was officially surveyed and why officials believed Hyndman Peak — now considered Idaho’s ninth-tallest — took the top spot for several years.

Tom Carlson, a National Map liaison for the U.S. Geological Survey, said that elevation was likely measured using maps, compasses and an altimeter — a device that uses barometric pressure to determine altitude.

In recent years, the U.S. Geological Survey launched its 3D Elevation Program, using technology called light detection and ranging, or LiDAR, to remeasure elevations across the U.S. LiDAR uses sensors attached to airplanes or helicopters to determine elevation based on how quickly light emitted from the aircraft takes to reach the Earth’s surface and return to the sensor.

Carlson helped organize ongoing LiDAR projects in Idaho. Earlier this year, the U.S. Geological Survey released some of its Idaho LiDAR data to the public, including measurements of Borah and other Lost River Range peaks.

The results put Mount Borah at 12,666 feet — 4 feet taller than people have long thought.

When will Borah elevation be updated?

One of the only places where you’ll find Borah’s LiDAR-pinpointed elevation listed online is at ListsofJohn.com, a website that catalogs U.S. mountain peaks, highpoints and other mountain information. It’s popular among hikers and mountaineers and allows recreationists to log their summit ascents.

The website is run by John Kirk, a Denver resident, who has long been interested in LiDAR and its mapping capabilities.

“Over the last decade or so, LiDAR has become a thing, but it was something in the background where only experts had access to it,” he told the Statesman in an interview.

As the U.S. Geological Survey has released its 3D Elevation Program data, Kirk has gathered the information to update his site. While combing through the data, he noticed some information related to Colorado’s 14,000-foot peaks, or 14ers, was different than existing maps. Later, he saw that the long-accepted state highpoint for Pennsylvania was inaccurate, according to LiDAR data.

So he wasn’t surprised to learn that Mount Borah was slightly taller than cartographers have long asserted.

“Just because that’s what was always said, doesn’t mean it’s true,” Kirk said.

But don’t expect to see the 12,666-foot elevation reflected on many maps in the near future. Carlson said it may take another two or three years for the U.S. Geological Survey to update its online maps. Still, that’s orders of magnitude faster than maps used to be changed, he said.

“In the past, a place like somewhere in Idaho where there’s not a lot of people at, that map might have gotten made in, say, 1900 and never updated,” Carlson told the Statesman. “Or maybe it was updated in 1950. And so it took a long time and a lot of handiwork to update those maps.”

One other measures of elevation, the metal benchmark medallions that can be found on many peaks, likely won’t be changed to reflect the LiDAR updates, according to Dan Determan of the National Geodetic Survey.

Determan said many of those markers serve as monuments for hikers or geocachers. What’s more, Determan said, the National Geodetic Survey doesn’t use LiDAR for its measurements so the new data has no significance for its work, which is used for land surveys.

Kirk said it could take some time for the general public to adopt the new elevation information too.

“People are a little attached to their paper maps,” he said. “It’ll probably be a bit of time still before it seems like it’s readily accepted.”