Nice pictures!
Just in case someone (like me before I checked it out) is confused about what a Belding's Sparrow is. It's a subspecies of Savannah Sparrow. But according to my National Geographic field guide the beldingi subspecies is supposed to be darker than the bird on the picture. This one looks more like the nevadensis subspecies, but I have no experience with either of them, so I'm not sure.
/Thomas