Members of the Beta Theta Pi fraternity painted today’s Rock. From the Northwestern Chapter Web site:
“The Rho chapter at Northwestern was founded in 1872 as a result of the General Convention which met in Richmond, Virginia that year. After its removal from campus in 1994, Rho was reinstalled in 1997 by 10 founding fathers. Today, the chapter contains over 70 brothers and is one of the largest houses at Northwestern.”