To navigate in the Google Street View panorama, click inside the window and drag your cursor. To change your location along Old Highway 120, click on the arrows that appear when your cursor is over the window.
Street View mode typically takes a few seconds to load, and you'll see a map view at first. If the map view never goes away, it likely means that you don't have Adobe Flash installed on your computer.
The Street View crew didn't get lucky with the light conditions the day they rolled through Groveland - the Yosemite Pines area, for instance, is definitely more inviting and less blurry than it appears here - but it is nifty that you can see the shadow of the Street View car in the foreground, along with the elaborate apparatus used for filming.