In an effort to decrease the frequency of alcohol-impaired driving, San Juan County, New Mexico recently established the San Juan County DWI (SJC-DWI) Facility for treatment of first time DWI offenders. San Juan County exhibits a severe drinking and driving problem: it has the second highest rate of alcohol-related vehicle fatalities in the United states, and ranks first in counties in New Mexico for frequency of repeat and aggravated DWI offenses. The City of Farmington, the program's location, is a border community to the Navajo Nation, and the SJC-DWI's client population is predominantly (approximately 70 percent) Navajo. The SJC-DWI program blends a 28-day period of incarceration with several intervention components that are tailored to the program's predominantly Native American population. The SJC-DWI is distinctive in that it employs intervention components that are culturally sensitive, is set in a rural setting, serves a predominantly Native American population, and is focused solely on first-time DWI offenders. As such, the program addresses several gaps in the DWI prevention literature. While some preliminary data suggest that there has been a large reduction in DWI re-arrest for SJC-DWI clients, no controlled and comprehensive evaluations of the program have been accomplished to date. Proposed here is a 5-year project that would comprehensively evaluate the SJC-DWI program. The research design to be employed in the project will be a 2-group randomized design, with one group receiving the SJC-DWI program and the state-mandated DWI school, and the second receiving a 28-day period of incarceration only and the state mandated DWI school (a condition similar to DWI sentencing before the establishment of the SJC-DWI program). A large cohort of participants will be followed over a three-year time period for DWI recidivism, while a randomly selected subgroup of participants will be followed intensively for a two-year time period during which intervention-related data will be collected. The proposed project will definitively determine the preventive impact of the SJC-DWI program, make a significant contribution to the alcohol and DWI prevention research literature, and point towards important innovations in prevention practice.