Mount Rainier with Columbia Crest at the center / Wikipedia

Mount Rainier's true summit is no longer where it once was. Today, if you climb Rainier, the centerpiece of Mount Rainier National Park, you'll summit at a spot called Columbia Crest. Officially, according to the U.S. Geologocal Survey, it's 14,410 feet. That figure was established in 1956, based on traingulations taken in 1914. It's stood for over a century. Columbia Crest is a big hunk of ice affixed to Rainier's massive crater rim. If you've seen photos of moountaineers celebrating a successful climb, they'll be standing on the ice cap of Columbia Crest, raising ice axes triumphantly into the deep blue sky. 

But in recent years, climbing guides spotted an area along the crater rim that appeared higher than where they stood on Columbia Crest. It's a rocky fist on the southwest rim that is exposed each summer as ice melts away. Word got to Eric Gilbertson, a mountaineer and mechanical engineering professor at Seattle University. Gilbertson has spent a few years climbing and measuring the highest peaks in the Cascades as a personal project. He'd climbed Rainier before, and he'd also noted the rocky outcrop as possibly being higher than Columbia Crest When Gilbertson heard rumblings from others that something seemed...different at Rainier's summit, he knew he needed to find out for sure. 

Gilbertson and his twin brother Matthew have climbed the highest points in 145 countries around the world. 

Gilbertson secured funding from the American Alpine Club to take GPS readings from Columbia Crest and the rocky spot some climbers suggested might be the new high point. He waited until the end of August to allow time for the ice to melt away to get the most accurate reading possible. That's also when the last USGS survey mapped the peak in 1998. 

On August 28, Gilbertson and a couple partners set up their equipment at the top of Rainier. They took readings at Columbia Crest and the rocky promontory 500 feet away. Gilbertson's data confirmed what his fellow climbers had seen. Columbia Crest measured 14,389.2 feet. The rocky point on the southwest rim measured 14,399.6 feet. Not only had Rainier's summit shrunk, it had exchanged places. Columbia Crest was no longer the high point.

"This is not just a case of a more accurate measurement," Gilbertson says. The original measurement of Rainier was done with triangulation, long before the advent of GPS. But that technique is surprisingly accurate. The peaks's height had also largely been confirmed with GPS measurements in recent decades.

"My measurements are accurate to +/-0.1ft, the same as the 1988 and 1998 measurements, says Gilbertson. [Columbia Crest] has also been measured with Lidar in 2007 and 2022, which showed considerable shrinking between those years. There is zero doubt that Columbia Crest has melted significantly."

According to Gilbertson's calculations, Columbia Crest has melted down nearly 22 feet since the 1998 ground survey. This matched his suspicions, and it's a significant amount of melting. 

The shrinkage appears to be increasing too. Until 1998, the height of Rainier's summit stayed relatively constant. At least, it matched the USGS survey results from 1914. But Gilbertson wanted to see how much the elevation had changed in recent decades. Using data from lidar surveys of the mountain, Gilbertson was able to calculate that Columbia Crest had shrunk about 0.7 feet annually from 1998 to 2007. That jumped to 1.5 feet between 2023-2024. Gilbertson's data suggests the new high point overtook Columbia Crest about a decade ago. 

The American Alpine Club grant will fund more surveys like this for Gilbertson. He wants to climb more of Washington's ice-capped peaks to see how they're faring. Not well, is the likely scenario. 

Rainier's new (unofficial) high point is rock at least, so it won't be shrinking. At least, not faster than the normal pace of erosion. But it's a stark reminder of how climate change is transforming even things as seemingly immovable as mountains. 

"It is kind of sad for a mountain to be shrinking like this," he says. "I used to think of mountains as generally staying a constant height in the short term at least. But that doesn't seem to be the case in recent years."