Changes to Some Opening/Closing Dates for Services and Facilities – Check Back for Updates
Some of the opening/closing dates for facilities and visitor services in the parks have changed due to weather and/or other circumstances. See link for details and match to locations on the park map (under "Park Tools," bottom left, this page). More »
Road Conditions (Entire Park) and Road Construction Delays (if Entering/Exiting Hwy. 198)
Expect 20-minute to 1-hour construction delays on main road through parks (Generals Hwy) until Memorial Day weekend (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 »
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.
Air Quality -- Nitrogen Deposition
Nitrogen is essential for all living things. It is found in solid earth and in the atmosphere. Small amounts of nitrogen move in a dynamic cycle involving the atmosphere, oceans, lakes, streams, plants, and animals. Depending on the form and amount in the environment, nitrogen can serve as a nutrient, enhancing growth and productivity, or as a toxin, causing ecological damage or harming human health.
Human activities (emissions from vehicles, electric utilities, industrial plants and agricultural activities) have added levels of nitrogen rivaling or exceeding contributions from natural sources.
There has been a slow, continuous increase in atmospheric nitrogen deposition in park watersheds as well as around the world. However, in spite of increasing nitrogen deposition, there has been a decrease in the dissolved nitrogen that has been measured in the water flowing out of mid and high-elevation park watersheds. More than four decades of research provide unequivocal evidence that nitrogen have altered, and will continue to alter our nation's lands and waters. In these parks we have measured increased nitrogen deposition and its effect on water quality and it has the potential to alter terrestrial plant communities in ways that we cannot anticipate.
For further information, visit the National Atmospheric Deposition Program web site.
Did You Know?
The 16 steep, narrow road miles from Ash Mountain to Giant Forest include 130 curves and 12 switchbacks. A vehicle-length advisory of 22 feet (6.7 m) is suggested for the 12 steepest miles within that stretch.