In this study we focus on individual and environmental determinants of urban trail use in three diverse urban settings: Chicago, Dallas, and Los Angeles. Explanatory factors include individual psychosocial and health characteristics, distance between home and trail, and land-use and social characteristics of trailside neighborhoods. Model results suggest that intrinsic motivation, general health status, perceived trail safety, perceived miles between home and trail, and neighborhood connectivity were significantly related to probability of trail use and extent of trail use, while working-class status, commuting distance, and physical barriers to the trail were negatively related. Efforts to increase perceived trail safety, accessibility, and awareness about trails thus may result in a higher rate of trail use and more time spent on urban trails.