A large rock slide carrying monster boulders and a few spruce trees and alder bushes has blocked a well-trodden path leading to Nugget Falls, just south of Juneau's Mendenhall Glacier.
The slide broke loose around noon on Wednesday, roughly 100 yards south of the glacier.
The smell of freshly broken spruce still lingered in the air Thursday afternoon, when Mendenhall Glacier Visitor Center personnel trekked over to the slide area for a closer look.
"This will affect people. The whole area has changed," said Larry Musarra, director of the visitor center.
He said, quoting the late writer Edward Abbey, that people who travel over the rocks certainly have the right to put life and limb in danger.
The rocks are still unstable. Chris Steuer, a federal environmental consultant visiting Juneau from the East Coast, started clambering over the rocks Thursday with a companion before he realized that their path was a shaky one.
"It's not so stable as others I've been on. I started thinking, this is maybe not a good idea," Steuer said, after safely arriving on the other side.
Musarra said that slides in the vicinity of the glacier tend to happen in the fall, when the area is "slushy."
"This is the biggest slide I've seen in the last few years," said Musarra, who has worked at the visitor's center for three years and lived in Juneau for about 10 years.
Rock slides are relatively common in the Juneau area because of its steep rocky ridges, geologists said Thursday.
The steep ridges are susceptible to large slabs of rock peeling off their sides but are even more risky due to snow avalanches.
The retreat of the Mendenhall Glacier also destabilizes its surrounding rock.
"The sidewalls do tend to become unstable," said Roman Motyka, a Juneau-based glaciologist with the University of Alaska Fairbanks.
The glacier acts like a force exerting pressure against the rock. When it retreats away from the rock, the pressure releases and fractures in the rock open up more. As a result, more water can get down inside the fractures, said Chris DeWitt, with the Bureau of Land Management's Juneau Mineral Information Center.
"All those joints start opening up and weathering ... big chunks will fall off in those fracture planes," DeWitt said.
"The steeper the slope, the better chance of a slab falling off," DeWitt added.
Elizabeth Bluemink can be reached at firstname.lastname@example.org.