Maybe. I'm not sure about the subspecies ID if either of these. They do look a little darker and more strongly marked (especially the first one), but I'm not sure. I have a bit of personal experience with Belding's and just don't know if the coloring is quite in range for that ssp here.
Belding's are definitely found in California as you said, but they're rather localized. They're not widespread throughout the state, meaning you can't expect to have them generally. I can't pull up an eBird map now, but I'd like to know if the spot these were seen is a known Belding's spot. Savannah subspecies are often distinctive, but there can certainly be some ambiguity at other times.