Since January 1998, a group of Texas 6–12th science and math teachers have met several times per year to learn first-hand about how scientific instrumentation and its use. They followed the development of the Stratospheric Observatory for Infrared Astronomy (SOFIA) Echelon Cross Echelle Spectrograph (EXES) and its prototype ground-based instrument TEXES. In addition to learning about the technology of astronomical instrumentation, the teachers explored scheduling and preparation for observing runs, as well as a wide range of astronomical topics. Participating in observing runs with TEXES at Gemini North and the NASA Infrared Telescope Facility (IRTF) in Hawaii provides the ultimate field trip. The participants report their increased knowledge of astronomical concepts and of the culture of professional astronomy. The participants have shared their experiences with each other, other teachers, and their students.