I can't spot a distinguishing characteristic on this Sparrow

I photographed this sparrow on the shore of the Salton Sea, southeast California last week. I need help spotting distinguishing characteristics.

The bird looks like a Savannah Sparrow, nevadensis subspecies for a few reasons. Most SAVS that occur on the coast are a a darker, chocolate brown and have yellow in the front half of their superciliary (the line above the eye). The non-coastal races are a medium brown like this bird and have no or very pale yellow in the superciliary.. The face also has the dark line through the eye and the dark moustache streak.

If you saw the front of the bird you would some light streaks on the upper breast and flanks and a spot in the middle of the breast. And then there is that tiny bill and the pinkish legs...

Greg

Slobird, thanks for your input. I had ruled out Savannah Sparrow, because the birds we see here in Alaska have an unmistakable yellow spot in-front of the eye.

Gary