Photographer Mary Ellen Mark is known for shining a light on big issues, from youths living on the streets in Seattle to the prostitutes of Bombay. So some might have scratched their heads when she decided to take her 400-pound Polaroid 20-by-24 Land Camera to that frivolous, over-the-top American rite of passage known as the prom. Traveling to high schools all over the country between 2006 and 2009, she photographed a diverse mix of young people—some looking cocky, some looking ebullient, some looking utterly scared to death—for gorgeous black-and-white portraits, which document all the awkwardness and heartache of being a teenager. See her photos now at Janet Borden, Inc. and feel grateful you’re not still in high school.

Tuesdays-Saturdays, 11 a.m. Starts: Dec. 21. Continues through Jan. 12, 2012