A Previously Undiscovered Glacier Has Been Found on South Sister Mountain

The Oregon Glacier Institute estimates the glacier is over 100 years old and likely formed in the mid-1800s during the Little Ice Age.

The Three Sisters
By Shannon Gormley

When it formed last year, the Oregon Glacier Institute set out to track the state's disappearing glaciers. In the process, it discovered a new one.

The organization has announced that it discovered the previously unmapped glacier on the north face of South Sister Mountain. OGI estimates the glacier is over 100 years old and likely formed in the mid-1800s during the Little Ice Age.

"Despite more than a century of exploring the Oregon High Cascades by mountaineers and government scientists, we know very little about our own backyards," OGI president Anders Carlson said in a statement. "The age of discovery is not over, even here in Oregon."

There is no state or federal oversight agency that monitors glaciers, and Oregon's glaciers haven't been mapped in over 70 years. Previous mapping efforts by government agencies mainly used aerial photographs to find glaciers. It's likely that previous mapping efforts missed the new glacier, which is tucked into a glacial cirque, simply because they were unable to see it from the air.

OGI is currently working to determine the health of Oregon's glaciers, and determine how many are still contributing to Oregon's waterways by producing meltwater year after year. Last fall, OGI declared two South Sister glaciers dead.

Related: Scientists Held a "Funeral" for a Glacier That Melted in Central Oregon.

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