Porterville was settled by the members of the Porter Family. Sanford Porter Jr., while on duty as a scout in the winter of 1857-58, rode into a canyon so rocky and difficult to travel that he named it Hardscrabble. Here he found a stream of water and abundant timber, ideal for a sawmill. In 1859 the family hauled machinery and supplies over the Wasatch Mountains by pack mule and built the first sawmill in Morgan County. In 1860 Sanford Sr. and Nancy Warriner Porter built a cabin five miles east of the mill and spent the first winter here. During the following two years, four sons, Chauncy, John, Sanford Jr., and Lyman built log homes and moved their families into the valley.
For several years after the settlers came, Chief Washakie and his band of Shoshone Indians returned each fall to hunt, fish and dry meat, and pick berries.
In 1863 English converts began to arrive. In 1864 a branch of the Church of Jesus Christ of Latter-day Saints was organized.
When the railroad was built through Morgan County, the Porter Mill furnished ties to lay the track from Echo to Devil's Gate.