WALLA WALLA, Wash. -- Most colleges try to discourage students' fondness for drink. Walla Walla Community College not only encourages students to enjoy alcohol, it also bottles and sells the stuff.

And for the city of Walla Walla, the school's courses on reds and whites have made for an unexpected infusion of green, helping turn the local wine industry into the city's main source of economic growth.

The...