In 2014, the Geological Society of America sponsored an Accessible Field Trip, designed to demonstrate best practices in accommodating a wide variety of participants with disabilities during a field experience. During the trip, an aide was deployed to assist two student participants with sensory disabilities, one with low vision and the other with deafness. The experiences and interactions between the assistant and the students were compiled into a thick description, which was subsequently analyzed through self-reflective case study. The lived experiences of the participants and the assistant are interpreted to describe the efficacy of personal assistants in field study. Effective assistants maintain an awareness that students with disabilities have varying comfort levels with self-advocacy. An effective assistant also facilitates a positive perception of the student with a disability within the full group. Key skills of the personal assistant include awareness of spatial placement, communication, and flexibility. Three fundamental recommendations are presented for the effective use of personal assistants: (1) open and continuous communication as part of pretrip planning, (2) trip leaders must be willing to be flexible and adaptable with their field sites and learning goals, and (3) trip leaders must recognize social and spatial parameters of assisting students with disabilities. Ultimately, trip planners must become familiar with the personal and cultural backgrounds and abilities of their students to plan for an effective instructional excursion.