This series is comprised of correspondence, minutes, ephemera, clippings, publications, and other material regarding Sylvia M. Broadbent's involvement with local, national, and international organizations and her political activism on behalf of environmental issues. Records document her participation on citizens committees, membership in clubs and associations, review of environmental projects, and attendance at public hearings.

Broadbent frequently contacted government entities and administrators regarding environmental projects and their impact on archaeological and other cultural resources. Organizations with which Broadbent was affiliated include the De Anza Cycle Park Citizens Advisory Committee and Off-Road Vehicle Subcommittee, both divisions of the Riverside County Parks Department, the Sierra Club San Gorgonio Chapter, the board of directors of Victoria Avenue Forever, Amnesty International USA Adoption Group 163, The American National Red Cross, and others.

Because many folders maintain the original filing scheme of the creator, select records outside the scope of this series are included.