I saw this request at the Madera County message board Ancestry.com:
"Looking for info on Douglas, ae 61, & L. Elizabeth Austin, 55, who were farming on Barendas Road, Twp. G, Madera Co.,CA, on 20 Feb 1920. Search of Madera GenWeb was negative."
After checking the census record you listed, I checked the family in previous records. Douglas and son, Lewis, were recorded in San Francisco in 1910 and in Larimer County, Colorado in 1900:
1900 Federal Census
AUSTIN, Douglas, born December 1855 in Michigan
AUSTIN, Lizzie, born April 1866 in Ohio
AUSTIN, Wesley, born November 1881 in Nebraska
AUSTIN, Lewis, born October 1883 in Nebraska
AUSTIN, Agnes, born June 1885 in Nebraska
AUSTIN, William H., born August 1889 in Nebraska
AUSTIN, Frank, born May 1892 in Nebraska
AUSTIN, Bertha, born November 1896 in Nebraska
I returned my attention to California, where I found Wesley AUSTIN in the California Death Index:
AUSTIN, Wesley; born 20 November 1882 in Nebraska; died 2 June 1948 in Fresno County; mother's maiden name: MAY
Searching the Fresno newspapers, I found a wealth of information, including the obituaries for both Elizabeth AUSTIN and Douglas AUSTIN (who was listed as A. Douglas AUSTIN in the newspaper and Stephen A. AUSTIN in the death index.)
I also found the obituaries for two of the sons, George and Wesley.