The 4-H Youth Development Program, with support from the Noyce Foundation, began the 4-H Science Initiative with the goals of engaging more young people in science-related fields and increasing the number of youth pursuing higher education and careers in STEM. The Youth Engagement, Attitudes, and Knowledge (YEAK) study provides insight into the population served by 4-H Science programs, their experiences, their attitudes toward science and related fields, how they engage in science in their communities, and their aspirations. While the Year 3 YEAK findings reflect a sample of youth participating in 4-H, they also contribute to the national dialogue on science education in other informal learning environments. (author abstract)