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.
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Did You Know?
In Yosemite Valley, dropping over 594-foot Nevada Fall and then 317-foot Vernal Fall, the Merced River creates what is known as the “Giant Staircase.” Such exemplary stair-step river morphology is characterized by a large variability in river movement and flow, from quiet pools to the dramatic drops of the waterfalls themselves.