Lois B. DeFleur became the university's fifth president upon Clark's retirement in 1990. During her nearly 20-year tenure the university experienced its most significant growth. She oversaw substantial additions to the student and faculty populations, vastly expanded research activities and funding, formalized Binghamton's fundraising efforts, expanded the campus' physical footprint by approximately 20 buildings, launched Binghamton's "green" efforts for which they are now nationally recognized, transitioned the school from Division III athletics to Division I and catalyzed the biggest increase in academic rankings to date.