Oral histories with Julia Morgan family and colleagues from the Regional Oral History Office at Bancroft Library, available online via the Internet Archive:

• Volume 1: https://archive.org/details/histprojinterviews01julirich (editor Suzanne B. Riess)
  • Interviews with Walter Steilberg, Robert Ratcliff, Evelyn Paine Ratcliff, Norman Jensen, Jack Wagstaff, Edward Hussey, George Hodges
  • Reminiscences of the Department of Architecture, UC Berkeley, Warren C. Perry
• Volume 2: https://archive.org/details/histprojinterviews02julirich (editor Suzanne B. Riess)
  • Interviews with Mary Grace Barron, Dorothy Wormser Coblentz, Bjarne Dahl, Bjarne Dahl, Jr., Edward Hussey, Hettie Belle Marcus, Polly Lawrence McNaught, Catherine Freeman Nimitz, Flora and Morgan North, Kirk O. Rowlands, Norma Willer, Quintilla Williams
• Original Audio: https://archive.org/details/cabeuroh_000150 

Hearst San Simeon State Historical Monument Oral History Project: Over 100 interviews conducted by Hearst Castle staff, with castle employees, guests, and other individuals associated with San Simeon. Searchable via the Kennedy Library’s catalog. Cal Poly can provide physical on-site access to oral history transcripts. Additional copies are available at other institutions, try searching WorldCat to find out who else holds copies.