Social contact norms are used by managers to establish standards for regulating visitation of wilderness areas so that visitors can attain adequate experiences of solitude. This study expanded on current conceptions of social contact norms to provide a theoretical and empirical basis for understanding how such norms are formed. Using person perception, stereotyping, and socialization theory and the concept of cognitive schemata, a conceptual framework was built to explain how visitors come to judge certain groups as appropriate or inappropriate in a wilderness area. Seven research hypotheses were proposed and tested using a database consisting of responses to a mail questionnaire survey of 800 permit requestors and 95 interviews with visitors at Aravaipa Canyon Wilderness, Arizona. The first hypothesis, that wilderness visitors would regard some types of groups as appropriate and other types of groups as inappropriate in the wilderness area, was supported. Norms for encountering 13 types of groups were estimated from written questions and drawings, and paired picture comparisons allowed ranking of six types of groups. Encounters with lone hikers, small groups, medium-sized groups, birdwatchers, youth groups, school classes, and rangers were considered more appropriate than encounters with hunters, horseback riders, packstock users, and nude bathers. Logit and multinomial logit models were used to test the six remaining hypotheses, which concerned the influences of socialization and other processes on development of social contact norms. To test the hypotheses, norms for encountering six types for groups were predicted from demographic and other variables. The results indicated that norms for encountering small groups were not affected by social class or race; affiliation with a small group during a wilderness visit was associated with a dislike of large groups, membership in a conservation organization had no such association; members of conservation organizations preferred fewer encounters with hunters; membership in a conservation organization also prompted the respondents to dislike encounters with horseback riders; females, older visitors, and people with children disliked encountering nude bathers; and inexperienced and less self-reliant visitors enjoyed encounters with rangers. Theoretical, managerial, and social implications of these results were then discussed.