• Rainbow over Half Dome

    Yosemite

    National Park California

Hantavirus in Yosemite

Hantavirus is a rare but serious disease that humans can contract through contact with infected rodents or their urine, saliva, blood, or droppings. Since HPS was first identified in the United States in 1993, there have been 62 cases in California residents and over 600 cases nationally. Approximately 12 percent of deer mice carry hantavirus.

The deer mouse (Peromyscus maniculatus) is the primary reservoir for Sin Nombre Virus, the strain of hantavirus responsible for the human cases in Yosemite National Park, and most human cases in the United States. The deer mouse is found throughout most of the United States, including Yosemite National Park.

For additional information on preventing HPS, visit the Centers for Disease Control and Prevention (CDC) hantavirus website or California Department of Public Health (CDPH) website.


View frequently asked questions about hantavirus in Yosemite.

News Releases and Updates


General Information about Hantavirus


Information for Health Care Providers

Did You Know?

El Portal Boulder Bar

At the east end of El Portal, just west of Yosemite National Park’s boundary, changing river gradients, glacial history, and powerful floods have created a boulder bar with boulders much larger than typically found in such deposits. This is no ordinary boulder bar, however, for it contains massive boulders over a meter in diameter and weighing many tons.