McMahon, Marghe May was born on May 7, 1954 in Palo Alto, California, United States. Daughter of Merritt Norval and Ruth Evelyn McMahon.
Bachelor in Psychobiology, University of California, Santa Cruz, 1975;
postgraduate, University of California, Santa Cruz, 1977-1978.
Biologist, neuropharmacology Syntex Research, Palo Alto, 1975-1976. Freelance artist Santa Cruz, California, 1976-1981. Sculptor, modelmaker Lucas Film, San Rafael, 1981-1992, 20th Century Fox Orion, Chris Walas Inc., Los Angeles, 1983-1988.
Freelance sculptor San Francisco, 1981-1988. Specialist glass fibre reinforced cement restoration in historic buildings, 1984-2002. Fabricator/project manager museum design Academy Studios, Novato, 2001-2002.
Prosecuting pathology department Deltagen, Inc., San Carlos.
Sculptor, modelmaker GJP Productions, Gaffney, South Carolina, Westport, Washington, 1988, Premavision, Sausalito, California, 1987, 88. Painter/modelmaker Colossal Pictures/USFX, San Francisco, 1986. Painter Rob Bottin Productions, Los Angeles, Dallas and Pittsburgh, 1996-1997.