Campo Santo was founded in September 2013 by Jake Rodkin, Sean Vanaman (both lead designers and writers on The Walking Dead, Season 1), Nels Anderson (lead designer on Mark of The Ninja), and artist Olly Moss, best known for his redesigns of classic movie posters. Chris Remo (formerly of Double Fine) was hired in February 2014.
In April 2018, Campo Santo was acquired by Valve Corporation in Bellevue, Washington, where all 12 employees moved, to continue developer of In the Valley of Gods.
Development on the studio's first game, Firewatch, officially began in January 2014, with a release date originally slated for 2015. The official release was announced on Campo Santo's blog.
Firewatch was released to mostly positive reception, with a Metacritic score of 81. It has drawn comparisons to other first-person, story-focused games such as Gone Home and Dear Esther.