There are three stages in this multi-cache. You will probably want to drive from stage 1 to stage 2. It is a short, pleasant walk from the recommended parking area to stage 2, where there is little parking, and from there to the final stage.
Richard Bertram "Bert" Barrett was born in 1884 in New Almaden, the son of a quicksilver miner. He served as the Chief of Sanitation in the Santa Clara County Health Department, dying at the age of 74 in 1959. Bertram Road in New Almaden is named for him. His remains are interred here, at the starting point, in the Great Mausoleum in Oak Hill Memorial Park. The Mausoleum is open daily from 9 AM to 4:30 PM.
For stage 1, enter the Great Mausoleum and find the final resting spot of "R. Bert Barrett" in the Camellia Room. In the niche to the right find the birth year of Robert and subtract 1109. This is ABC.
In 1898 at the age of 13, a shotgun blew off almost half of Bert's left arm in a terrible hunting accident. In compliance with the laws of the time, his severed appendage was buried in the Hacienda Cemetery in New Almaden.
For stage 2, find the final resting spot of Bert's arm in Hacienda Cemetery . There is very little parking at the cemetery but it is a short walk along Bertram Road from the suggested parking to the cemetery. (Yes, that Bertram Road.) The bulletin board near the grave has more information about Mr. Barrett's life including some photos. There is also a plaque commemorating the cemetery being placed on the National Register of Historic Places. Subtract 1022 from the year the plaque was dedicated, this is DEF.
The cache is located a short distance from Hacienda Cemetery at N37 10.ABC W121 48.DEF.
You can validate your puzzle solution with certitude.
While you are in New Almaden you should consider looking for another multi-cache, GC7XC7N, "New Almaden Walking Tour".