The "Arb"consists of approximately 880 acres (360 hectares) of land adjacent to the College and was created under the leadership of President Donald J. Cowling and Professor Harvey E. Stork in the 1920s. Professor Stork and Superintendent of Grounds D. Blake Stewart ("Stewsie") were responsible for much of the early development of the Arb, and their influences can still be seen and felt in many places. Stork and Stewsie were remarkable land managers, and it can be argued that they were among the nation's first restoration ecologists. In particular, their planting of upland forest trees and wildflowers in the Upper Arb (Stork Forest) decades ago is now coming to impressive maturity.

Education

The Arb is used extensively as an outdoor classroom by a number of Carleton courses, especially in Biology and Geology. Students are able to carry out observations and experiments in a natural setting within walking distance of the campus, an invaluable asset for classes with a field component. It is also used by other educational institutions at levels from pre-school to graduate school, as well as for professional research programs.

Conservation

The Arb has been a State Game Refuge for decades, and it serves a valuable role in providing habitat for species of diverse natural communities. As ecological restoration proceeds in the coming decades, the conservation value of the Arb will be substantially increased. Small populations of two rare turtles are found in the Arb: wood turtles (Clemmys insculpta, a threatened species in Minnesota) and Blanding’s turtles (Emydoidea blandingii, a species of special concern). Two threatened plant species were discovered in the Arb in the 1990's: ovate-leaved skullcap (Scutellaria ovata) and kitten-tails (Besseya bullii). Other rare species may remain undiscovered.

Recreation

The most common recreational use of the Arb is by casual visitors who come to walk, run, ski, fish, or simply enjoy being outdoors. There are occasionally organized athletic events in the Arb, and both Carleton and St. Olaf teams, as well as the Northfield public schools, use the Arb as a training facility for cross-country running and skiing.