Thirty-three local emergency medical services (EMS) authority agencies serve the 58 counties in California. A local EMS authority (LEMSA) in California governs either EMS providers in a single county or several counties combined. Each LEMSA dictates widely different treatment and transport protocols for its paramedics. Preliminary data for this thesis substantiate previously published literature, which shows broad disparities in prehospital care and patient outcomes among LEMSA jurisdictions in California. Although previous research has established the problem of geographic EMS disparities, nothing definitively explains their cause. This thesis contends that the decentralized LEMSA system is the chief culprit for EMS disparities in California, based on an analysis of the available California EMS performance-measure data. Regression analysis does not identify a single factor to explain the problem; the only constant across all LEMSAs in California is that their treatment protocols and training standards to maintain local accreditation vary widely. Unfortunately, the striking lack of performance-measure data--a data desert--for EMS throughout the United States limits the scope of research seeking to explain the inconsistency in EMS care.