There was a John Barring that was married in 1858 in San Francisco to Margaret Evans. Perhaps those were his parents. Most of the records of births, deaths and marriages in San Francisco were lost in the earthquake and fire in San Francisco in 1906, but a man named Jim W. Faulkinbury has transcribed many of the records from the San Francisco Call newspaper from 1869-1900. Sometimes those records help in tracing families. See his site at:
On that website there is a Bertha Barring (sister?) married in 1894, but unfortunately no mention of John.
Another explanation for our lack of information is that sometimes headboards have been replaced and the faded names were abbreviated by time.
Skagway Death Record; San Francisco Call; Familysearch.