The Department of Earth and Planetary Sciences (EPS) at the University of New Mexico offers two field geology courses (EPS 319L, Introductory Field Geology, and EPS420L, Advanced Field Geology). Prior to summer 1986, these courses were taught during the academic year, on the weekends. Over a two year time span, despite some faculty consternation, the department converted both classes into full-blown summer field geology courses. These continue to be offered as two separate, independent classes for several reasons. Introductory Field Geology is required of all EPS geoscience majors and has attracted numerous students from institutions outside New Mexico. All mapping is done using a paper topographic map and/or an air photograph base, with, eventually, the aid of a handheld global positioning system (GPS) device. Given that topographic map skills remain essential for effective computer- and GPS-based mapping, we emphasize these traditional techniques within the limited time span (three weeks) of the course. Despite the fact that all students are expected (required) to have passed the standard array of core undergraduate courses in the geosciences, the backgrounds of the students, including level of previous field experience, vary considerably. Consequently, the approach taken in EPS 319L is one in which strong emphasis is placed on providing rapid feedback and focusing maximum instructor attention on the students who need it the most. As one means of providing rapid feedback to all of our students, we utilize a “postage stamp” map exercise as an essential component of each mapping project. After at least one day of introduction to the project, the entire class focuses on a morning of mapping in a small, yet very revealing project area. The maps are turned in after a group discussion of the postage stamp area, and detailed feedback, using several rubrics, is provided to all students by the end of the day (but these maps are not graded). In field geology courses, where the goal is to maximize student field learning within a limited time frame, the postage stamp exercises have proven to be an effective way to provide timely instructor input and reinforcement of burgeoning student skills. Student evaluations of the course support the use of the postage stamp exercises for each map project; these exercises improve the instructor’s ability to assess final map products in an even more rigorous and consistent fashion.