The program currently employs 15 full-time counselors to provide comprehensive substance abuse treatment services on three dedicated treatment units with 240 treatment beds. Inmates are referred to this program if they have an identified need for residential substance abuse treatment and are within 12 months of consideration for release. As part of funding requirements, the program was increased from 4 months to 6 months in length, and participants were separated from the general inmate population for all activities. The funding source (National Institute of Justice Residential Substance Abuse Treatment for State Prisoners) also required the adoption of a cognitive treatment model. These program modifications were implemented in Spring 1998. The main objectives of the evaluation project were to establish a system to evaluate the operations and effectiveness of TOW, as well as to assist program staff in developing and implementing intake, discharge, and follow-up instruments, along with evaluation protocols to document inmate characteristics and changes over time related to substance use/abuse, mental health, social functioning, and criminal behavior and attitudes. The primary evaluation sample consisted of adult male inmates of the TOW program. The program began admitting inmates on April 18, 1997 and has seen a total of 736 prisoners as of December 30, 1998. Data were collected from the inmates by using a series of standardized instruments: a semi-structured interview and several self-administered questionnaires. This report focuses on TOW subject satisfaction with the program. Fifty-eight percent were "very satisfied" and 34 percent were "satisfied." Evaluation instruments are described in detail, along with participants demographics and criminal history. Substance-use patterns are described as well. Implications of evaluation work thus far and future analysis are discussed. 3 tables