Through a grant from the National Science Foundation, FHI 360 experts developed Great Science for Girls: Extension Services for Gender Equity in Science through After School Programs (GSG) to provide inquiry-based, informal science learning programs that will stimulate girls’ curiosity, interest and persistence in science, technology, engineering and mathematics (STEM) and break down the barriers of gender stereotyping. Working with intermediaries (organizations that provide training and technical assistance to afterschool programs in their region) around the country, GSG provided curricula research, professional development and consulting services to promote the concept that science is, indeed, a “girl thing.”