The former National Training Group (NTG) athlete turned heads during the 2015 season at U.S. Alpine Championships in Sugarloaf, Maine when she snagged a podium amongst juniors in giant slalom. Her solid stint as an NTG athlete allowed her to propel on to the D Team for the 2016 season. She did it again in 2016 when she grabbed a pair of podiums at U.S. Alpine Championships in Sun Valley, Idaho and topped the super-G podium amongst juniors. She made the jump to the C Team in 2017, and to the World Cup in 2018, where she scored her first World Cup points at Lenzerheide, with a 19th place in alpine combined. That finish snagged her a spot on her very first Olympic Team in PyeongChang. Mangan continued her successful skiing career at Dartmouth College where she earned first team all American status in the giant slalom. After her NCAA success, Mangan made it back to the Stifel U.S. Alpine Ski Team for the 2023-24 season for speed.

In the 2023-24 season Mangan secured some of her best results to date. This included multiple Europa Cup podiums in super-G and downhill as well as multiple top 30 World Cup results, also in speed. 

When she's lucky enough to be home, she loves spending time with her five siblings and parents, partaking in various sports, heated debates, and unrivaled excitement.