Mountaineer explores and tests the wide space in between post-rock, shoegaze sludgegaze and post-metal. Passages, the follow up to their 2017 Lifeforce Records debut, Sirens & Slumber was written from beginning to end in order and nothing was deleted or rewritten. It was an experiment in writing as a stream of consciousness. Vocals and drums were added to the demo version later. Drums were provided by new contributor, Patrick Spain while Clayton Bartholomew wrote and recorded all of the guitar and bass parts for the record. The band also uses some interesting sound layers on Passages including Xylophones, piano, tambourine and bells. Produced, engineered and mixed by Ben Hirschfield and mastered by Mike Kalajian at Rogue Planet Masteringk, the album is comprised of two 20 minute long tracks, broken into passages. The songs are tied together by several overarching themes, but are mainly focused around the struggle to grasp the concept of mortality.