# Glacier retreat in the American West

> Live situation record from CLSTR: https://clstr.news/situations/glacier-retreat-in-the-american-west
> Updated: 2026-10-28T15:37:10.000Z. Sources: 6. Developments: 3.

Research indicates that the western United States has lost nearly 300 glaciers since the mid-20th century due to rising temperatures. At the mid-century mark, the region contained approximately 1,450 glaciers, but the total surface area has since decreased by roughly one-third.

Scientists attribute this accelerated melting to a “double blow” of rising summer temperatures and winter precipitation increasingly falling as rain rather than snow. This prevents the replenishment of glacial masses. The loss is particularly acute in the lower 48 states, where smaller glacier sizes make them more vulnerable to warming compared to larger glaciers in Alaska.

A study published in the Proceedings of the National Academy of Sciences, involving researchers from Portland State University and the U.S. Geological Survey, confirms that six western states—California, Colorado, Idaho, Montana, Oregon, Washington, and Wyoming—have lost more than one-third of their glacial cover since the 1950s. The research found that total glacier area has shrunk by 35% and volume has decreased by 33%. 

Specific regional impacts include Washington state, which holds the largest concentration of glaciers at about 114 square miles, and the Beartooth-Absaroka Mountains of Montana, where ice thickness is decreasing by roughly 1.5 feet annually. Andrew Fountain, a geology professor at Portland State University, noted that these losses serve as “tangible evidence of continued climate warming.”

The disappearance of these ice reserves poses risks to freshwater supplies for agriculture, local ecosystems, and hydroelectric power generation.

## Timeline

### 2026-10-28: Western US glaciers lose one-third of cover since 1950

A study by Portland State University and the USGS shows Western US states have lost over one-third of their glacial cover and 300 glaciers since the 1950s due to climate warming.

2 sources. https://clstr.news/cluster/western-us-glaciers-lose-one-third-of-cover-since-1950

### 2026-10-22: Western United States loses nearly 300 glaciers to warming

Since the 1960s, the western United States has lost nearly 300 glaciers, reducing total glacial surface area by one-third and threatening water and energy resources.

2 sources. https://clstr.news/cluster/western-united-states-loses-nearly-300-glaciers-to-warming

### 2026-10-14: Glaciers in the American West: 300 have disappeared

A study shows over 300 glaciers have vanished from the lower 48 U.S. states, with remaining ice melting faster than global averages due to rising temperatures.

2 sources. https://clstr.news/cluster/glaciers-in-the-american-west-300-have-disappeared

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Cite as: Glacier retreat in the American West. CLSTR, https://clstr.news/situations/glacier-retreat-in-the-american-west