Motorhome parking in or near Walnut Creek 10/23-10/26

I am attending a seminar in Walnut creek and am looking for a place I can park my motorhome for a few days to save money on hotel room. Any ideas? I can tow my Toyota and use it for the commute.

Thanks

There might be a few in Pacheco and maybe  concord cant remember if I seen any in Martinez. I remember driving by the ones in concord.

Wal-mart parking lot.