He enlisted and served in the United States Air Force for four years, attending an overseas program of the University of Maryland, College Park during that time.

During an academic leave, Crowley became a fellow with the United States Environmental Protection Agency in 1973, and served as the director of institutional studies for the National Commission on Water Quality in 1974.

He oversaw a dramatic expansion of the institution, both in size of the campus, as well as significant increases in student and faculty numbers.

Also during his tenure, Crowley served on the board of directors of the National Association of State Universities and Land Grant Colleges (NASULGC).

In 1989 he spent as semester as visiting reader at Brasenose College, Oxford, and chaired the Nevada Rhodes Scholar Committee.

In 2015, Crowley became president of Sierra Wellness Connection, one of two companies that were awarded Reno's first business licenses for cultivating medical marijuana.