The Butcher of Yosemite is a fictional nickname featured in the Syfy Original Series Defiance. It is applied to the character of Joshua Nolan. Joshua Nolan was a soldier in the Pale Wars. In 2029 he participated in a battle against the Votans at Yosemite Valley. At this point in his life, Nolan was known to be brutal and merciless. His actions during the massacre at Yosemite Valley earned him the nickname the Butcher of Yosemite.
Nolan's past has come back to haunt him several times. Datak Tarr found an audio recording of Nolan from this era and used it as leverage to sabotage Nolan's endorsement of Amanda Rosewater during her re-election campaign as Mayor. 
The insane Votanis Collective rogue General Rahm Tak recalled the massacre, citing how he had been present at the battle and noted how a once beautiful waterfall ran red with Votan blood for days due to Nolan's actions. As a means of thumbing his nose at Joshua, Rahm Tak began referring to himself as the "Butcher of Tulsa". 
A battle between Nolan's volunteer freedom fighters against Rahm Tak's forces cost the lives of nearly everyone in his group. The overwhelming guilt that Nolan felt, as well as the influence of a piece of alien ArcTech in his brain, caused Nolan to begin suffering intense hallucinations. He began seeing images of himself adorned in the attire of the massacre era. The "Butcher" hallucination first appeared to Nolan when he discovered the hanging corpse of Indur - the father of one of Nolan's dead volunteers, who had hanged himself out of grief. 
The Butcher also began whispering in Nolan's ear when he was at the NeedWant and later at the Darby Building, inciting him to pull his gun on the recently-returned Datak Tarr. At a diplomatic meeting between town leaders and administrators from the legitimate Votanis Collective, the Butcher had Nolan believing that someone had planted a bomb in the building. Acting erratic and driven to extremes, Nolan ultimately shot and killed the V.C. prime minister, Silora Voske.