[2] In 1902, Col. Mudd moved his family to Los Angeles, California,[3] where he worked as a consulting engineer for the Guggenheim Exploration Company.

The company ran an up-to-date, 65-bed hospital for its employees, built scores of low-cost houses for them to live in, and helped to run schools, sports clubs, welfare centers, and summer camps for their families.

He was a trustee and former president of the Southwest Museum, a member of the Board of Governors of the Los Angeles County Museum of Art, and member of the advisory committee of the Henry E. Huntington Library and Art Gallery.

[3] As Chairman of the Southern California Symphony Association, Mudd is credited with saving the Los Angeles Philharmonic.

[12] Fellow copper baron William Andrews Clark Jr. had founded the Philharmonic in 1919, but he had exhausted his fortune supporting the orchestra.

To oversee the Philharmonic, the Southern California Symphony Association was created in 1933 with Mudd as chairman.

Mudd led fundraising efforts to enable the Philharmonic to continue performing through the Great Depression.

[12] Mudd is also credited with starting the Philharmonic's tradition of taking the stuffiness out of high culture.

[12] He was initiated as an honorary member of the Beta Psi chapter of Phi Mu Alpha Sinfonia, the national fraternity for men in music, in 1941.

[7] He helped to plan Claremont's new undergraduate college of science and engineering that was chartered in 1955, shortly after his death.

[17] For three years, beginning in 1934, she was the Los Angeles County Council commissioner of the Girl Scouts.

[13][16] In 1939, Time magazine described her as "Tall, dark, [and] slender" and as "a typical society matron, noted for her large and lavish parties, her charitable activities, [and] her ancient Roman jewelry (dug up in Cyprus)".

[20] Mudd died of a heart attack on April 12, 1955, at his home in Beverly Hills, California.

[7][5] Mildred and family members contributed $2 million to endow Harvey Mudd College,[22] which awards degrees in science and engineering.