They released the tracks 'Young' and 'Thru' on Triple J Unearthed in January 2015. On January 6, 2015, the duo released their first EP, "Vallis Alps." The EP featured both 'Young' and 'Thru' as well as two other songs: 'Oh!' and 'Reprieve.' 'Young' went on to feature in the Triple J Hottest 100 in 2015 at #27. Off the success of their debut EP, Vallis Alps announced their first Australian tour dates in August of 2015 including playing at Splendour in the Grass on July 26. The pair moved to Sydney in late 2015. Their 2015 was capped off with a nomination for the J Award for Unearthed Artist of the Year in 2015.
The duo's follow-up to their debut EP was the release of a new track titled 'Fading' on November 24, 2016. The track featured in the Triple J 2016 Hottest 100 at #94 marking the second straight year a song of theirs featured upon the list. 'Fading' was followed up upon with their track 'East' on March 20, 2017. In addition to the new track, the duo announced a world tour including dates in Australia, the United States, and one date in London. Both 'Fading' and 'East' were featured on their sophomore EP titled "Fable," released on March 31. The EP featured two additional tracks: 'Serity' and 'Run.'