Many managers face the challenge of monitoring rates of visitor encounters in wilderness. This study, conducted in 1991 at Alpine Lakes Wilderness in Washington State: (1) provides estimates of encounter rates through use of several monitoring methods, (2) determines the relationship between the various measures of encounter rates, and (3) determines the relationship between various indirect predictors of encounter rates and actual encounter rates. In order to develop a better understanding of the relationship between these various monitoring methods, this study used exit surveys, trip diaries, wilderness ranger observations, trained observers, mechanical counters, trailhead count observations, and parking lot vehicle counts. This data publication includes the data associated with this study, which found that encounter rates differed dramatically from weekdays to weekend days at high-use places studied. Estimates of encounter rates also varied substantially across methods used. Rather than conclude what method is best, this report seeks to help the manager decide which method is most appropriate for use in a particular wilderness, given the issues being addressed. It should also help alleviate some of the problems managers have in prescribing monitoring systems, by forcing more precise definition of indicators.