Brigham City, city (1990 pop. 15,644), seat of Box Elder co., N Utah; inc. 1869. It is the center of a large farm area served by the Ogden River project. Sheep, cattle, wheat, sugar beets, and orchard fruit are raised. There is petroleum refining and the manufacture of propulsion systems and construction materials. Brigham City was founded as Box Elder in 1851, and its name was changed to honor Brigham Young in 1856. To the west is the Golden Spike National Historic Site (see National Parks and Monuments, table), which marks the spot where the transcontinental railroad was completed in 1869.