That is a RealtyTrac listing. There has been some debate about their listings on Trulia, as they are pre-foreclosure listings, and thus are not really for sale. If the owner ultimately pays their mortgage, the home will most likely not be for sale. RealtyTrac posts these listings trying to get people to sign up for their service.
Ultimately, the best source for homes is the MLS, which also includes some actual foreclosures. If you want help finding homes that are for sale in Mill Valley, we would be happy to help you.