This article discusses the conversion of abandoned, redundant, or unwanted infrastructure into parks to meet the needs of Los Angeles County residents. The author draws primarily from experience gained through the development and implementation of the Puente Hills Landfill Park Master Plan. The landfill is 1365 acres in size and has been closed since 2013. Completed in 2016, the Master Plan proposes to transform 142 acres of the landfill into the county’s first new regional park in over 30 years. This case study covers topics such as interagency coordination, community engagement, park master plan development, and funding to develop, operate, and maintain the park. Lessons learned are applicable for the conversion of landfills to parks in other places as well as the transformation of other infrastructure into parkland, especially in park-poor areas where the remaining opportunities to create new parks are largely limited to the restoration of degraded lands.