The first facility opened in 1965 in Lander, Wyoming at Sinks Canyon. June 8, 1965 marks the date of the founding and the first trip beginning at the trailhead of Hidden Valley Ranch where 100 male students went into the Wind River Range. In the beginning, NOLS struggled with finances to provide necessities for outdoor trips, so Petzoldt and his early team developed the “uniform” made of Salvation Army donations. The school began to grow in the early years and in 1966, women were allowed to enroll. In 1967, the Adventure Courses began for young boys aged 13–15.