Fillmore lies in the Pavant Valley, a broad farming area on what used to be the seafloor of Ancient Lake Bonneville. To the west and north a broad, flat area spreads for miles, broken only by a few rocky hills. To the east the juniper-covered slopes of the Pavant Mountains rise to 10,000 foot peaks. Farmland surrounds Fillmore, extending north and south, following the base of the mountains. To the west the land is dry, being known as the Sevier Desert.
In 1851, four years after Mormon pioneers settled in Salt Lake City, the territorial legislature determined to establish the territorial capitol in the Pavant Valley, being centrally located in the state. On October 28th the site at Fillmore was selected and the city was named after U. S. President Millard Fillmore. Construction of an elaborate statehouse was begun, but only one wing had been completed when in 1856 the legislature determined to move the capitol to Salt Lake City.
Fillmore continued on as a farming community, with a population of 2,253, as of the 2000 census. Interstate 15, the main north-south artery through Utah, passes through Fillmore. Before the interstate was built, U.S. Highway 91 was the avenue of travel through Fillmore, passing down Main Street. The section of the old highway from the interchange at the north end of town to the one at the south end is now designated Utah Highway 99. Much of the old highway north and south from there is extant and serves as a frontage road along the freeway. They lead north to Holden and south to Meadow. Utah Highway 100 heads west from Fillmore for several miles and then turns north to junction with U.S. Highway 50 about an hour's drive away.