Born in Crested Butte, Colorado, Montag moved to California after graduating high school where she enrolled at the Academy of Art University in San Francisco. During freshman orientation, she met Lauren Conrad who was then a featured cast member on the MTV reality series Laguna Beach: The Real Orange County. After Montag and Conrad transferred to Fashion Institute of Design & Merchandising in Los Angeles, Conrad received her own spin-off series The Hills, which premiered on May 31, 2006. Montag was featured in the series sharing an apartment with Conrad while studying at the Fashion Institute of Design & Merchandising. She eventually left the Fashion Institute in fall of 2005 when she was hired at Bolthouse Productions. According to Montag, she dropped out because she "did not find the school challenging." Within two years, she was promoted to event planner at Bolthouse, before being fired and then re-hired.
