I didn't find their deaths in Ancestry, FamilySearch or the California Pre-1905 Death Index. Death certificates weren't required in California until 1905 although some counties had death certificates before 1905.
There is a Monterey County volunteer at www.gengathering.com that may be able to help you. You do have to create a user ID and password to enter this web sites but access to the volunteer info is available.
Also, you might want to post your email address on your profile so volunteers can send you documents, etc. Successful Searching!