Enter the library through the main entrance (not the atrium), go up the stairs, and the entire West Wing (on the left) is Erdahl-Cloyd (EC).

2304 Erdahl Cloyd is the auditorium/lecture hall. For that, keep straight down the stairs to the left, past the silent reading room (on your left) and the creamery (on your right), and go up another flight of stairs. From there, 2304 EC auditorium will be on your right.