Yost is an unincorporated community located in northwestern Box Elder County, Utah, United States, on the north central slopes of the Raft River Mountains, some 100 miles northwest of Brigham City. The first name for the area was "George Creek" for a man named George Eddy Sanderson, an early range rider who came to the area with Charles Yost from th…Yost is an unincorporated community located in northwestern Box Elder County, Utah, United States, on the north central slopes of the Raft River Mountains, some 100 miles northwest of Brigham City. The first name for the area was "George Creek" for a man named George Eddy Sanderson, an early range rider who came to the area with Charles Yost from the Nevada Territory. Charles Yost remained in the area, becoming postmaster in 1887. After Yost built his cabin, he lived alone until he married Maria Larsen from Terrace, Utah, on the south side of the mountains. For four years she was the only woman living in Yost.