The plunging waterfall seen in this image is The Cascade, found just off Route 140 coming into Yosemite Valley before the junction with SR 120. If you think the image looks a bit hazy, look closely at it in the larger size. You are looking at falling snow!
Special thanks to Leon Turnball, who helped me correctly identify this waterfall (yes, I can sometimes confuse locations after the fact!), and whose web waterfall gallery has an excellent photographic directory of California waterfalls.