海迪·蒙塔格，Heidi Blair Pratt is an American television personality, singer, fashion designer, and author. Born and raised in Crested Butte, Colorado, United States of America, she befriended Lauren Conrad in 2005. In 2006, Montag came to prominence after being cast in the MTV reality television series The Hills, which chronicled the personal and professional lives of Conrad, Montag, and friends Audrina Patridge and Whitney Port. During its production, she briefly attended the Fashion Institute of Design & Merchandising and was employed by event planning company Bolthouse Productions. As the series progressed, Montag began dating fellow cast member Spencer Pratt, which ultimately ended her friendship with Conrad. Their ensuing feud became the central focus of the series, and was carried through each subsequent season.