• Giant Sequoia Trees

    Sequoia & Kings Canyon

    National Parks California

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  • Parks Institute Stage 1 Fire Restrictions June 1, 2013

    Due to high fire danger, Sequoia & Kings Canyon National Parks are instituting fire restrictions inside the parks. More »

  • Road Construction Delays (if Entering/Exiting Hwy. 198)

    Expect minimal construction delays on main road through parks (Generals Hwy) through June 2013 on weekdays generally from 7 a.m.-6 p.m. See link for schedule. Call for 24-hour road conditions info: 559-565-3341 (press 1, 1, 1). More »

  • Vehicle Length Limits Have Changed in Sequoia NP (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 new vehicle length advisories for your safety and the safety of others. More »

  • Some Opening/Closing Dates for Services and Facilities May Change – Check Back for Updates

    Some opening/closing dates for facilities and visitor services in the parks may change due to weather or other circumstances. Call 559-565-3341 or send us an email using the "Contact Us" link below the main menu (bottom left, this page).

  • You May Have Trouble Calling Us. Use the "Contact Us" Link (Bottom Left) to Send an E-mail.

    We are experiencing technical problems receiving some incoming phone calls at the parks. We apologize for the inconvenience. Please keep trying to reach us or check this website for frequently-asked questions. The search box (top, right) may be helpful.

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?

Sign indicating no pets allowed.

Dogs are not permitted on any park trails or on the summer shuttle, except service dogs. This allows for more frequent wildlife sightings, ensures that other visitors and wildlife will not be annoyed or frightened by dogs, and saves cleanup on trails. You can take dogs on leashes on US Forest Service trails.