This article reviews the major reforms in California probation policies in the last decade and, relying on newly available data, describes how those changes have reshaped probation populations. We discuss the research literature on probation workers, which offers some key insights to guide our inquiry about the law enforcement and social work dimensions of probation work. We then report data on how the nature of probation work has changed in the context of these policy and population changes, using statewide survey data on probation officers and supervisors.