The Sierra County Clerk-Recorder (at the courthouse in Downieville) should have a death certificate for your grandfather who died in 1969. The state should have one as well but you will get a copy from the county much faster. (If you know the county I think it is better to get a copy from them. If you don't know which county the event occurred in, then go to the state.) California began collecting vital records in 1905.
Sierra County has birth records from 1857, marriage records from 1852 (when the county was formed from Yuba County), and death records from 1864. Some of the early records are incomplete but are well worth checking.
What time period was Bill Bakotic there? You might check on him as well.
Sierra Co. GenWeb Coordinator