In light of discussions about the benefits and tradeoffs of integrated STEM education, we present a case that focuses on an apparently promising context for integrating mathematics and science. First- and second-graders observed changes in prairie plants over a year and sought a way to locate their plants in the prairie, as a planned prairie burn would soon destroy the top growth. They agreed to use compasses and pacing to write directions from a common landmark to the plants. Later, the class attempted to reinterpret their conceptions of location and wayfinding in the context of two new representations: a 2-dimensional map and a hoop on the floor that depicted the outline of the prairie. During this conversation, children struggled to integrate their memories of distance and unit-length, experienced within the prairie, to inscriptions that presented an external perspective of the same space. Some problems appeared to stem from the authenticity of the task, which inspired solutions that disrupted the teacher's mathematical agenda. To promote STEM education, educators need to be aware of the task solutions that children are likely to invent, thoroughly address children's understanding of representational conventions, and select tasks in which model-test and revision play a prominent role.