Running through the middle of the campus is an area known as the canyon: a 26 acre watershed that is the headwater of Crystal Springs, a major tributary of Johnson Creek. Over the years, canyon maintenance has been attended to by members of the Reed community, particularly students during annual Canyon Day work parties. Some of the wildlife that inhabit the canyon, include heron, kingfisher, beaver, nutria, opossum, raccoon, and a variety of waterfowl. The biology department frequently uses the canyon for research. Students often conduct independent projects using plant or animal species that live in the canyon.
A canyon restoration strategy has brought about the removal of non-native invasive plants and restoration of native plant communities. Reed's outdoor pool was demolished in fall 2000, ensuring an unobstructed waterway for fish passage. Fish ladders provide for safe migration of native fish populations to the lake area from the lower creek. The overall plan outlines a 10-year improvement and maintenance strategy for enhancing the best features already exemplified in the watershed.
The first cross canyon bridge, constructed in the 1930s, was replaced in 1959 with one of unusual design. The only one of its kind in the world, the bridge was the result of more than a year's research by the architect and a plywood company. It was supported by two cantilevers of pre-stressed plywood and covered with a thin canvas membrane, eventually determined to be too slippery. The current bridge, built in 1992, won the coveted "Excellence in Concrete" award from the American Concrete and Aggregate Producers Association. For its initiation, students created a "super-highway" look to the bridge, complete with a traffic divider-remnants can be seen in the small concrete patches in the center of the bridge.