Sego boasted a population of nearly 500 people more than 80 years ago. Located in Sego Canyon five miles north of Thompson Springs, Sego began its existence as a coal mining camp for American Fuel Company workers who had begun working Henry Ballard’s coal mine in the Book Cliffs area around 1912. The coal from the mine was loaded onto railroad cars and transported down a five-and-a-half mile railroad spur to Thompson. The town was originally known as Neslen at first, and was notable for its racially segregated housing. In 1918, the town’s name was changed to Sego (in honor of Utah’s state flower) when Chesterfield Coal Company bought out AFC. The mine, which struggled financially throughout much of its existence, closed for good in 1947. Today, a few ramshackle buildings remain, including the old store, a two-story wooden boarding house, along with a few dugout cabins, an explosives bunker, and several old foundations.(*)
Thompson is east of Crescent Junction and near I-70 at Sego junction. E. W. Thompson lived near the springs and operated a sawmill to the north near the Book Cliffs. It was also a prominent shipping point for cattle that were run in the Book Cliffs area. Stockmen from both San Juan and Grand counties used Thompson. The original name for this settlement was Thompson Springs, a name that has recently been revived and reinstated.