The impact of "The Great Lake Erie," an outreach program that aimed to improve visitor knowledge and attitudes about Lake Erie, is discussed in this evaluative study. "The Great Lake Erie" was presented as a two-part program consisting of a lecture and demonstration stage presentation and a series of exhibits. The program was open to school groups during weekdays and to the general public on weekends and evenings. Visitor behavior at the exhibits was monitored, and the 17 displays were evaluated on their attention-holding ability, knowledge impact, instructional component, accommodation potential, and self-directiveness. The highest rated exhibits tended to be self-directive and highly interactive. To assess knowledge and attitude changes related to the program, a pretest-postest questionnaire was completed by visiting adults and students. Students and adults responded differently to the program. Adults showed significant knowledge gain while students did not. On attitudes, students and adults were positive on the pretest, but only students showed a positive shift on the posttest. Positive feedback was obtained from teachers who participated in the program with their classes. A diagram of the display area and exhibit design, as well as observation form, are included. (ML)