This study is motivated by two research questions: (1) How does Culturally Congruent Instruction (CCI) influence American Indian (AI) students’ attitudes and achievement in natural resources science at a tribally controlled college/university (TCU)? And (2) What is the nature of the relationship between CCI course modifications and changes (or lack of) in AI students’ science attitudes and achievement at a TCU? Findings developed a Culturally Congruent Instructional Framework (CCIF) for use in TCUs and beyond.