The Early College High School Initiative is a program that provides college access to first-generation, minority, low-income and other under-represented populations by allowing them to take college classes while in high school. The goal of The Early College High School Initiative is to ease the transition to college by allowing the students to earn an associate's degree or up to two-years of college by the time they graduate high school. This study explored the transition experience of a group of early college high school students pursuing STEMM majors at a large Mid-western public university. Interviews were conducted with seven senior STEMM majors at the beginning and end of their final semester in the program. Interviews were also conducted with two high school math teachers, two high school science teachers, three high school administrators and seven college professors to gain insight into the roles they saw they played in the students' transition to college. The following six categories emerged from the analysis of the interview transcripts (a) attitude toward STEMM majors, (b) motivation, (c) preparation, (d) support, (e) interaction and engagement in the college culture, and (f) academic identity. The results were compared with several transition theories including Van Gannep's (1960) "Rites of Passage," Tinto's (1988) "Model of Institutional Departure" and Bridges' (2003) "Managing Transitions." Implications for universities, the early college high school at which the study was conducted, and other early college high schools is provided along with recommendations for future research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]