Access to parks and recreational opportunities contributes to physical activity and positive health outcomes. But who is responsible for building the healthy city, particularly where resources are limited? While neoliberal state restructuring and fiscal austerity measures have increased the responsibility of nonprofit organizations in local services provision, little is known about their role in promoting healthy urban environments. This article investigates the role of nonprofits in supporting parks and physical activity in Southern California and analyzes the relationships between levels of voluntary-sector activity and the socio-demographic, economic, and fiscal characteristics of municipalities. Results indicate that nonprofits are unevenly distributed and more active in affluent, fiscally stronger, suburban, conservative, and white municipalities, reproducing intra-urban differences underlying health disparities.