Although the final number won't be known until Saturday, city officials are planning for between 10,000 and 30,000, said Jim Buchanan, director of emergency services in Brigham City.
"That is the unknown," he said. "But we have been getting a lot of phone calls."
Police Lt. Mike Nelsen of the Brigham City Police Department said officers will be stationed at 12 intersections around the downtown area near the future temple site at 250 S. Main St., to help spectators file in for the 9 a.m. event.
Nelsen said his department doesn't expect any unusual problems and said things should rug smoothly.
"Parking is our biggest concern," he said. "We're anticipating a lot of people."