FOR THE ETHNOGRAPHIES, JOELLEN LAMBIOTTE'S 3-MONTH OBSERVATION AND INTERVIEWING OF ABOUT 135 INMATES AND STAFF IN 1975 WERE USED, TOGETHER WITH JOHN SMYKLA'S OBSERVATIONS AND INTERVIEWS OF INMATES AND STAFFS OVER A 7-MONTH PERIOD FROM AUGUST 1976 THROUGH FEBRUARY 1977. PLEASANTON REFLECTED THE SOCIAL DIVISION BETWEEN THE SEXES IN SOCIETY BOTH BY BEHAVIOR AND BEHAVIORAL NORMS AND ADHERENCE TO TRADITIONAL SOCIETAL SEXUAL STANDARDS. MALE-FEMALE RELATIONSHIPS WERE EXCLUSIVE; MALES INITIATED THE RELATIONSHIPS AND TENDED TO EMPHASIZE THE SEXUAL ASPECTS OF 'COEDING,' WHILE THE FEMALES WERE MORE CONCERNED WITH PERSONAL DYNAMICS OF COED RELATIONSHIPS. THE BEHAVIOR OF INMATES REFLECTED SOCIETAL ATTITUDES TOWARD DATING, SPORTS, AND LEADERSHIP, AS WELL AS THE SAME DIFFERENCES BETWEEN BLACK AND WHITE FEMALE INMATES. PLEASANTON DEMONSTRATED LESS RESTRICTED DAY-TO-DAY CONTACT BETWEEN STAFF AND INMATES, CONTACT THAT OFTEN SAW THE DEVELOPMENT OF FRIENDLY RELATIONSHIPS. ONE-THIRD OF THE STAFF EXPRESSED POSITIVE ATTITUDES TOWARD INMATES. THUS, PLEASANTON ACHIEVED A MORE NORMAL ENVIRONMENT THAN IS TYPICALLY FOUND IN SINGLE SEX INSTITUTIONS. HOMOSEXUALITY AT PLEASANTON HAD ALSO GREATLY DIMINISHED RELATIVE TO SINGLE-SEX INSTITUTIONS. TRANSFER INMATES ACCOUNTED FOR MOST HOMOSEXUAL OR BISEXUAL ACTIVITIES. THE COED RELATIONSHIP ALSO SEEMED TO LEAD TO A DECREASE IN DISRUPTIVE BEHAVIOR. THE ABSENCE OF RACIAL VIOLENCE OR HOMOSEXUAL ASSAULTS MAY BE ATTRIBUTABLE TO COCORRECTIONS, TO THE SEXUALLY INTEGRATED STAFF, OR TO THE STAFF'S EXPECTATION OF NO VIOLENCE. OVERALL, COCORRECTIONS AS OBSERVED AT PLEASANTON WAS A FAR SUPERIOR CORRECTIONAL ENVIRONMENT WITHIN WHICH TO CONTROL INMATES THAN NONSEXUALLY INTEGRATED PRISONS. TWO REFERENCES ARE PROVIDED.