The concurrent highways travel south through Brigham City and Ogden and separate near Ogden-Hinckley Airport.

By comparison, the longest stretch of western I-84 through a single state is the 375.17-mile-long (603.78 km) segment in Oregon.

[1] Every year, the Utah Department of Transportation (UDOT) conducts a series of surveys on its highways in the state to measure traffic volume.

[5] Crossing the Idaho–Utah state line, I-84 enters Box Elder County and the Curlew Valley near farmland that utilizes center-pivot irrigation before intersecting SR-30 at a diamond interchange.

The Blue Spring Hills form the southern border of Howell as I-84 continues southeast.

[6][7] Upon entering Weber County, the rail line that the highway has paralleled since Tremonton splits off eastward near Defense Depot Ogden, as the concurrent highways continue south past Farr West and Marriott-Slaterville before a Southern Pacific Railroad rail line, which traverses the Great Salt Lake on a causeway, crosses under the freeway.

[6][10] Splitting from I-15 near Roy, I-84 passes between Hill Air Force Base, which is to the south of the highway, and Washington Terrace before clipping the extreme northern portions of Davis County.

Once in the canyon, the carriageways of the highway split to accommodate the Devil's Gate-Weber Hydroelectric Power Plant.

Leaving the city the highway turns back east,[6][12] passing Devil's Slide, an unusual rock formation just off the freeway.

[17][18] Past the tree, the freeway passes through the town of Henefer before terminating at a directional T interchange with I-80 just south of the census-designated place of Echo.

Between Ogden and Brigham City, the highway was to be concurrent with US-91, then US-30S split off northwest to the Idaho border.

[27] The original routing of US-30S had the highway passing into Idaho west of Black Pine Peak; however,[28] the new I-84 was constructed to the east.

[41] A $20-million (equivalent to $34.9 million in 2023[38]) reconstruction of the US-89 interchange at the mouth of Weber Canyon was financed partly by the funding obtained by the state in preparation for the 2002 Winter Olympics in 1998[42] and was scheduled to begin in 2000.

[44] One of the sub-contractors on the job was found guilty of lying about sub-par work done on installation of roadside impact absorbers along this stretch.