Science, technology, engineering, and mathematics (STEM) careers are some of the highest paying options for students today. In addition, nations with strong STEM workforces and research capabilities are more competitive in the global market. One way to improve the number of people working in STEM is to improve the representation of underrepresented groups, like women, in these fields. Research demonstrates that for girls and women to persist, they must identify with their STEM career of interest which can be difficult for fields that have been historically, and remain, dominated by men. This study focuses on the role that an informal STEM education camp in the United States has on middle school girls’ STEM identity. The authors conducted a linear regression and hierarchical linear modeling analysis to determine the role that the program had on 145 female participants. The results indicate that a crucial component to STEM identity is girls’ levels of openness to challenge. The study indicates that informal STEM education programs should provide students with chances to be challenged in a way where they see these challenges as opportunities to grow rather than opportunities to fail.