Be Prepared! Tire Chains or Cables May Be Required in the Parks at Any Time
All vehicles must carry chains or cables when entering a chain-restricted area. It's the law (CA Vehicle Code, Section 605, Sections 27450-27503). Road conditions may change often. For road conditions, call 559-565-3341 (press 1, 1). 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 »
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 small gravity-defying cave formations found in Sequoia and Kings Canyon caves are known as helictites. They form due to the capillary action of acidic solutions and are composed of the minerals calcite and aragonite.