Milstead Doreen Milstead 
Finding Treasure Off the Coast of Old San Francisco – a Historical Romance [EPUB ebook] 

A woman living in the Klondike Territory decides to head down to San Francisco after getting an apparently legitimate treasure map from a local character, and when she determines that her theoretical claim is real, she runs into a charming but shady character laying claim to the very same piece of real estate, which happens to lie under the cold waters of the bay.