• View from Sourdough Mountain Overlook  A view looking down onto Diablo Lake. Photo Credit: NPS/Michael Silverman, 2010.

    North Cascades

    National Park Washington

There are park alerts in effect.
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  • State Route 20 closed at Mile Post 134, Ross Dam

    After a brief closure at Newhalem due to an avalanche and unstable conditions, SR 20 has re-opened to its normal winter closure point at MP 134, Ross Dam. The highway will remain closed from Ross Dam to MP 171 (Silver Star Creek) until spring re-opening. More »

  • Ross Dam Haul Road Closure Continues

    A short segment of the Ross Dam Haul Road between the Diablo Lake suspension bridge and the tunnel remains closed to public use due to continued recovery following a March 2010 landslide. The closure will remain in effect through 2014. More »

  • Notice of planned work for the Cascade River Road, fall 2014

    Visitors planning to access the park via the Cascade River Road after Labor Day should be advised that the Park Service is planning a fall closure of this road at Eldorado Creek (3 miles before the end of the road) in order to perform permanent repairs. More »

Geologic Activity

Rapid and Gradual Change Volcanic eruptions, landslides, floods and earthquakes remind us that this landscape is dynamic and ever-changing. These dramatic events can change habitat and ecosystems instantly.

  • Landslides triggered by heavy rains or earthquakes deliver sediment and large wood to streams. Landslides can also block valleys and form new lakes.

  • The Cascade volcanoes Mt. Baker, Mt. Rainier, Mt. St. Helens and Glacier Peak are active, and geologically speaking, very young features. Glacier Peak and Mt. Baker had significant cone-building eruptions 12,000 years ago. Evidence of earlier foundational calderas including the Hannegan Caldera were recently discovered in the northwest corner of the park.

  • Colossal ice sheets covered all but the highest peaks in the North Cascades as recently as 16,000 years ago.

  • More gradual changes occur over decades or centuries. Changes in air quality, growing season, temperature, precipitation and solar radiation can also be influential in altering ecosystems.

  • Pollution is carried by prevailing into the Cascades from Puget Sound. Winter storms and cold temperatures in the mountains scrub some of this pollution from the air and deposit it in lakes, streams and glaciers.

  • Changes in air and water temperatures are lengthening the growing season, melting glaciers, and shrinking the subalpine and alpine zones.

Critical knowledge of these rapid and slow processes is needed to manage the parks and understand results from plant and animal monitoring programs. Our ability to protect and preserve ecosystems hinges on an understanding of soils, air quality, geologic processes, climate change floodplains and other abiotic factors. The Geology program at North Cascades NP consists of three levels:

  • Inventories of important resources including soils, landslides, and glaciers.

  • Monitoring of key variables such as air and water quality, glaciers, climate, and streamflow.

  • Research linking inventory and monitoring observations with events and processes that are constantly changing.

Did You Know?

lupine is a common flower in dry sunny areas

In addition to Wilderness, Recreation Areas and National Park designations there are also five Research Natural Areas in the complex: Silver Lake, Pyramid Lake, Boston Glacier, Stetattle Creek and Big Beaver Valley.