Mary Marg Helgenberger (born November 16, 1958), better known as Marg Helgenberger, is an American film and television actress. She is perhaps best known for her roles as Catherine Willows in the CBS drama CSI: Crime Scene Investigation, and as K.C. Koloski in the ABC drama China Beach (which earned her the 1990 Emmy Award for Outstanding Supporting Actress in a Drama Series).
Marg (pronounced with a hard "G," unlike the name Marge) Helgenberger was born in Fremont, Nebraska, the daughter of Kay, a nurse, and Hugh Helgenberger, a meat inspector. She is of Irish and German descent and had a Catholic upbringing. Marg has one older sister named Ann and a younger brother named Curt. One of her first jobs, as a teenager, was spending her summers and her Christmas breaks working as a "boner" at the meat packing plant where her father was employed. Helgenberger played the French horn in her high school (North Bend Central High School) marching band. Until she went to college, Helgenberger wanted to be a nurse like her mother. Marg attended Kearney State College (now the University of Nebraska at Kearney) in Kearney, Neb., then attended Northwestern University's School of Speech in