city, Utah county, northern Utah, U.S. The city takes its name from the Spanish Fork River, along which the Spanish missionary-explorers Domínguez and Escalante (Escalante, Silvestre Vélez de) traveled in their 1776 survey of the region. In 1854 Mormon settlers established a fort alongside the river, around which a town grew. Prosperous farms and food-production industries provided the economic basis for the city until recent years, when technology and defense-related manufactures took a more prominent role. Inc. 1858. Pop. (1990) 11,272; (2000) 20,246.