Ruscelli limpidi e sequoie giganti, il parco di Yosemite compie 125 anni

Trees in Yosemite National Park are backlit by a sun turned orange by smoke from the El Portal Fire burning in the Stanislaus National Forest and Yosemite National Park in California, USA, 27 July 2014. ANSA/STUART PALLEY

A handout image dated 21 November 2007 and made available 29 August 2012 by DNC Parks & Resorts at Yosemite, Inc., showing the North Dome and Merced River in fall at the Yosemite National Park, California, USA. Officials at one of Americas most popular national parks warned some 1,700 visitors 28 August 2012 to be on the lookout for symptoms of a rare disease that has killed two vacationers at the Yosemite National Park in California. The so-called hantavirus is a rare, rodent-borne disease that is carried in the urine, saliva and feces of infected deer mice. If the virus is contracted, the symptoms appear one to six weeks after exposure with fever, headache and muscle ache, and progresses rapidly to severe difficulty in breathing and, in some cases, death. Yosemite officials believe that the three confirmed cases and one probable case occurred when the victims stayed at tent cabins in the parks Curry Village from mid-June onwards. They launched an outreach effort to contact all other visitors to the popular vacation spot. ANSA/KENNY KARST / HANDOUT HANDOUT EDITORIAL USE ONLY