Notes:  David acquired copies of these photos from the "Ned Wolfskill" collection at UC Davis in July, 2003.  He notes that the collection is also known as the
"Dart Collection" or "Dart/Wolfskill Collection" -- Iris (Taylor) Dart was Frances' 3rd child by Sam Taylor.
Also, Frances was the one who bequeathed the land to UC Davis.
Quoted from the minutes of the Regents of the University of California, 22 Oct 1965, available at http://dynaweb.oac.cdlib.org:8088/dynaweb/uchist/public/regentminutes/regents1065/@Generic__BookTextView/1441:

J. Wolfskill Tract Plaque
That the following wording be approved for a plaque to be placed upon the Wolfskill tract of the University of California:
University of California Experimental Farm
Wolfskill Grant

In 1842 John R. Wolfskill arrived here laden  with fruit seeds and cuttings. He was a true horticulturist and became the father of the fruit industry in this region. In 1937 Mrs. Frances Wolfskill Taylor Wilson, his daughter, bequeathed 107.28 acres to the University of California for an experimental farm.  From this portion of Rancho Rio de los Putos the University's research has since enriched the State's horticultural industry.
California registered Historical Landmark No. 804.