Nature & Science

Yosemite’s 747,956 acres (1,169 square miles), nearly 95 percent of which are designated Wilderness, are home to hundreds of wildlife species, and over a thousand plant species. Designated a World Heritage Site in 1984, Yosemite is known for its granite cliffs, waterfalls, clear streams, giant sequoia groves and biological diversity. Two Wild & Scenic Rivers, the Tuolumne and Merced rivers, begin in the park and flow west to the Central Valley. The park is a scientific laboratory of hydrology, geology and glaciology, amongst other sciences.

  • Fern fronds

    The native plants of Yosemite National Park are a significant part of the exquisite beauty and biological diversity of the park.

  • Two coyotes basking in the sun at Housekeeping Camp in winter 2018

    Yosemite National Park supports more than 400 species of vertebrates including fish, amphibians, reptiles, birds, and mammals.

  • Low intensity fire burning in forest
    Wildland Fire

    Fire managers use three tools to mimic fire's natural function in the ecosystem: prescribed fire, mechanical thinning, and wildfire.

  • El Capitan rises through smoke from a wildfire
    Climate Change in Yosemite

    What does it mean to conserve and protect a place during a time of large-scale environmental change?

  • Two park staff members planting willows in river corridor.
    Ecological Restoration

    Restoration projects seek to restore the natural balance of the park; you can see work in our meadows, wetlands, forests, and riverbanks.

  • Geologic formation at Taft Point
    Natural Features and Ecosystems

    Yosemite is a scientific laboratory of hydrology, geology and glaciology, amongst other sciences.

  • Image of groups of visitors using telescopes in a meadow in order to look at rock climbers.
    Visitor Use

    Social science methods provides us with tools to understand how visitor behavior and characteristics affect park resources.

  • Hazy conditions with Half Dome
    Environmental Factors

    Yosemite’s environment is healthy in many ways, yet it can be affected by factors such as poor air quality and invasive species, and noise.

  • Ranger measuring turtle before releasing it into the water in Yosemite Valley.
    Research and Studies

    A variety of scientific research is ongoing in Yosemite; animal species studies, invasive plant removal tactics, and user capacity issues.


Learn More

Yosemite Observer Dashboard: Physical Sciences


Visual, interactive information about current weather, stream flow, fires, and air quality conditions; all on one site! 

Last updated: August 21, 2023

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