Update: I've added an extra image at the end that shows the satellite imagery in the view from Keyes Road.
It doesn't happen often. I usually pass the right intersection once or maybe twice a week, but the most important factor is the air quality. It's almost always poor. Dust and smoke in the summer, fog and clouds in winter. There is a spot on the floor of the Great Valley (some call it merely the Central Valley) where one can see Half Dome and the other peaks around Yosemite Valley in the Sierra Nevada.
Here, courtesy of CalTopo.com is a guide to the peaks in the picture above.
POSTSCRIPT: Thank you for all the comments. Since there is still some controversy about whether this is Half Dome, it turns out that CalTopo also offers an image overlay on the viewfinder, so I have added it below. For those who feel the mountains in back are not "tall" enough, one needs to consider the curvature of the Earth over the 40-50 mile distance of the highest peaks in the view.