Piegan Blackfeet
Nancy Owen died in 1868, and John Owen's mental health deteriorated afterward. Fort Owen began to deteriorate as hostility from the Piegan Blackfeet and Owen's own mental health issues led far fewer people to visit the facility. When the Mullan Road opened in May 1864, it bypassed Fort Owen in favor or Hell Gate, Montana, in the Missoula Valley to the north, and Fort Owen's financial difficulties worsened.