• 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 »

Air Quality

Views from Thornton Lakes and Trapper's Peak. Photo Credit: NPS/NOCA Staff

Looking down into a hazy Skagit Valley from Trappers Peak.


Recognizing the value of the fresh mountain air of the North Cascades, Congress designated North Cascades National Park as a Class I area, affording it the highest degree of air quality protection. Unfortunately, the park lies in the path of prevailing westerly winds blowing from rapidly growing urban-industrial and agricultural areas in Puget Sound. The mark of humankind's activity can be found everywhere within the park. Windborne pollutants are deposited on glaciers in the park via precipitation. As the ice melts, water carries the pollutants into the food chain, moving from tiny aquatic insects called macroinvertebrates to fish to land mammals and eventually even back to humans.

Consequently, park managers are cooperatively involved with the US Geological Survey, the National Park Service's Air Resources Division and others to assess air pollution impacts and protect air quality related resources. The air resources management program at North Cascades includes monitoring, research and data dissemination. Pollutants such as particulate matter, ozone, acid deposition, mercury and pesticides have been monitored in the park. The park and cooperators have also studied the impact of those pollutants on visibility, water quality, vegetation and wildlife. Data are used to inform management strategies and regulatory activities that affect park air quality.

Did You Know?

Did You Know?

North Cascades National Park Service Complex includes 684,000 acres near the crest of the Cascade Mountains from the Canadian border south to Lake Chelan.