Use thousandth in a sentence. 1  coming last in a series of a thousand; 1,000th. 2  designating any of the thousand equal parts of something.
For other uses, see Brigham City (disambiguation). Brigham City is a city in Box Elder County, Utah, United States. The population was 17,899 at the 2010 census. It is the county seat of Box Elder County. It lies on the western slope of the Wellsville Mountains, a branch of the Wasatch Range at the western terminus of Box Elder Canyon.
Not to be confused with Promontory Point, Utah. Promontory in Box Elder County, Utah, United States is an area of high ground 32 mi (51 km) west of Brigham City, Utah and 66 mi (106 km) northwest of Salt Lake City.ising to an elevation of 4,902 feet (1,494 m) above sea level, it lies to the north of the Promontory Mountains and the Great Salt Lake.