Firm History

Don Crosby’s firm has evolved and the names changed since its inception in 1965. He has been a principal and owner in the following California based firms:

1965 CROSBY THORNTON HILL ASSOCIATES
Founded in San Francisco, CA

1968 FRANK L. HOPE AND ASSOCIATES OF NORTHERN CALIFORNIA,
San Francisco / San Jose

1972 CROSBY THORNTON ARCHITECTS
Re-established in San Francisco, and expanded to Modesto

1987 CROSBY YANDELL ARCHITECTS
Re-established in San Francisco

1989 CROSBY HELMICH ARCHITECTS
Merged w/ GHI Associates in San Francisco / San Jose

1996 THE RATCLIFF ARCHITECTS
Merged with Ratcliff Architects in Emeryville

2003 DONALD A. CROSBY, AIA, IIDA, ARCHITECT
Current practice in Sonoma County, CA
Principal Emeritus with Ratcliff Architects in Emeryville
Senior Architect (since 2011), Posard Broek + Associates in Marin County