• Giant Sequoia Trees

    Sequoia & Kings Canyon

    National Parks California

There are park alerts in effect.
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  • Sequoia and Kings Canyon National Parks Institute Stage 2 Fire Restrictions

    Effective July 28, 2014, the parks are in Stage 2 fire restrictions. See link below for more information. These restrictions will remain in place until further notice. More »

  • Road Construction Delays on Park Roads for 2014 Season

    Expect occasional 15-min. to 1-hour delays in Sequoia and Kings Canyon National Parks beginning Monday, June 2, weekdays only, between 5:30 a.m.-4:30 p.m., including delays to/from the General Sherman Tree, Crystal Cave, and Grant Grove. More »

  • Vehicle Length Limits in Sequoia National Park (if Entering/Exiting Hwy 198)

    Planning to see the "Big Trees" in Sequoia National Park? If you enter/exit via Hwy. 198, please pay close attention to vehicle length advisories for your safety and the safety of others. More »

  • You May Have Trouble Calling Us

    We are experiencing technical problems receiving incoming phone calls. We apologize for the inconvenience. Please send us an email to SEKI_Interpretation@nps.gov or check the "More" link for trip-planning information. More »

Ultraviolet Radiation

Since the 1970s, ozone high in the atmosphere has been decreasing. This allows more UV solar radiation to reach the earth's surface. The effects of increased UV radiation are not well understood. Several agencies and universities are studying links between UV radiation exposure and skin cancer and eye disorders in humans. UV radiation also has negative effects on plants and aquatic ecosystems.

UV radiation may also influence air quality in the parks. The smog obscuring park views is the result of chemical reactions that take place in the presence of sunlight. More UV radiation may speed up these chemical reactions and could increase the amount of smog and low-altitude ozone present.

In the mid-1990s Sequoia National Park was one of 14 national parks monitoring UV radiation as part of a UV network sponsored by the Environmental Protection Agency and the National Park Service. These measurements helped scientists better understand how changes in UV affect human health and various ecosystem processes. The network data are used for a variety of scientific studies including assessments of the effects of UV radiation on frog populations.

Ultraviolet Radiation Links
Environmental Protection Agency Ultraviolet Monitoring Program

Did You Know?

1890 map of Sequoia National Park.

Sequoia National Park is the second-oldest national park in the United States. It was created by Congress on September 25, 1890. General Grant National Park (the area now called Grant Grove), was designated soon after. Only Yellowstone National Park, created in 1872, is older. More...