Yosemite is known for the clear views of its many famous landmarks. Increasing pollution can create hazy skies and obstruct these views of El Capitan, Yosemite Falls, Half Dome and others. Visibility can be reduced by gases and fine particles, called aerosols. Increased aerosols mean more absorption and scattering of light which reduces the clarity, color, texture and form of the features we view. Sources of the visibility reducing pollution are both local (such as campfires) and regional (such as agricultural dust or wildland fires).

Along with the aesthetic impact there is also a health concern with increased haze. Fine particulate matter may collect in the nose, throat, bronchial tubes and lungs where it may cause respiratory infections.