Change on the Rocks

Retreating glaciers are informing the Land Trust’s conservation plans.

Few landmarks define our corner of the world like its three iconic, glaciated peaks. Mount Hood, Mount Adams, and Mount St. Helens bracket our region like sentinels—ever-present reminders that we live in a vast and extraordinary place.

As indelible as they seem, each of these mountains is a highly dynamic environment, continually shaped by the elements. Since many of the rivers in Columbia Land Trust’s service area originate from one of these peaks, such changes can have major implications for our conservation work.

Andrew Fountain, glaciologist and professor of geology at Portland State University, explores the ways glaciers respond to a changing climate. Fountain recently compared photographs of Hood, Adams, and St. Helens from the turn of the 20th century with field observations and Lidar, are remote sensing method used to examine Earth’s surfaces, to assess how the mountains’ glaciers have changed in the past 100 years. The results confirm what many casual observers might have guessed: Just about every glacier in the region is retreating in response to a warming climate. On average, the region has lost nearly half of its glacier area since 1900.

From 1907 to 2004, Mount Hood’s seven named glaciers have retreated, decreasing in size by an average of 34 percent. Mount Adams, which receives comparably less precipitation, is losing its glaciers at an even faster rate: 49 percent between 1904 and 2006. Crater Glacier, which sits in the bowl of Mount St. Helens, is actually advancing, but only because of the mountain’s unique shape and orientation.

While observations from Mount Hood and Mount Adams may raise concerns about the region’s future water supply, Fountain says the threat is low because groundwater and snowmelt minimize the effects of smaller glaciers. There are some areas closer to the mountains, however, where the impacts may be more significant. North of Mount Hood, the orchards of the Hood River region could face challenges given that the area relies on glacier melt for 30 percent of its water in the summertime.

Columbia Land Trust’s conservation team plans its efforts using the best available science. In addition to current data on areas with threatened wildlife, prime habitat, restoration potential, and on areas facing development pressures, the team must try to anticipate how a changing climate will influence its priorities going forward.

Fountain notes that with a gradually warming climate, there are winners and losers when it comes to habitat. “In our glacier-fed rivers, we have a few species of kryal [i.e., cold-loving] midges. As those glaciers disappear and that water warms up, those guys are gone, but those species will be replaced by others that prefer warmer water. Is that good or bad? It depends on who’s asking.”

For the Land Trust, conserving land forever means striving to be as resilient as the mountains that shape our skyline.