Rangelands are the dominant ecosystem type in San Luis Obispo County, California. They provide a diverse array of ecosystem services to society, including forage production for livestock, water regulation, and carbon sequestration, among others. The conversion of rangeland ecosystems to urban development and intensive agriculture influences the degree to which these landscapes can provide ecosystem services. However, rangeland conversion is not well documented at the county level in California. This study examined (1) the extent of rangeland conversion in the county during the past twenty years, (2) the key factors influencing conversion, and (3) the perceptions of ecosystem service provision held by ranchers and land managers in the region. We used a mixed-methods approach including geographic information systems analysis, surveys, and semi-structured interviews in order to address these three questions. In the area mapped in our study. 11.4% of rangelands were converted during the last thirty years. Conversion is largely influenced by estate taxes and other challenges to inheritance. We found that ranchers and rangeland managers perceive ranching and livestock grazing to be the most compatible land use on rangelands in the region. Furthermore, ranchers perceived a notable change in cultural services resulting from rangeland conversion in the county. These findings provide insight from ranchers and land managers into the drivers of rangeland conversion in San Luis Obispo County and the importance of cultural services in rangeland management in the county.