This two-part field lesson for mid- to upper-level undergraduates connects allochthonous inputs to the invertebrate consumers that depend on them. After preparing students with background information such as the stream continuum concept, ‘brown’ versus ‘green’ food web components, and invertebrate functional feeding groups, students will be ready to embark into the stream. During the first part, students will sample organic matter using a variety of equipment, sort the organic matter into leaf packs, and deploy the leaf packs. During the second part, students will collect the leaf packs, inventory the inhabiting aquatic macroinvertebrates, and identify functional feeding groups present. Students will reflect on their experience by drawing a diagram of a detritus-based food web, writing a paragraph explaining the food web, and making comparisons of their data to data from other locations in the activity worksheet.