This study combined the activity involvement and place attachment scores of trout anglers at Montauk State Park (Missouri, USA) into a typology of recreation specialization. The framework was used to explain anglers' knowledge of park resources. Highly specialized anglers were more knowledgeable about the park than those who were less specialized. Although utilization of interpretive media was related to resource knowledge, this relationship was fairly weak. These findings suggest that a visitor segmentation procedure based on recreation specialization can be a useful way to accomplish some management objectives at state parks, such as environmental education. (Contains 3 tables.)