With serious problems plaguing California's juvenile justice system, the efficacy of incapacitating juveniles in the Division of Juvenile Justice (DJJ) correctional facilities must be reexamined. California's youth incarceration patterns offer an opportunity to analyze the validity of incapacitation theory as it applies to young people. Under incapacitation theory, counties with higher youth incarceration rates are expected to experience accelerated reductions in juvenile crime. Failure to demonstrate reduced crime rates through higher levels of juvenile incarceration calls incapacitation theory into serious question as an effective youth crime reduction strategy. This study examines California's juvenile incarceration and crime trends over the past 47 years. In addition to statewide trends, county-by-county youth incarceration practices and crime patterns are examined to determine differential outcomes between high incarceration and low incarceration counties. (Contains 6 tables and 43 endnotes.) [Funded in part by the Ernst Van Loben Sels/ Rembe Rock Foundation and Haigh Scatena Foundation.]