 US @-@ 89 meets the current alignment of US @-@ 91 in the southern outskirts of Brigham City , turning east for an overlap on the city 's southeast bypass . ( SR @-@ 13 and SR @-@ 90 are the former alignment through Brigham City . ) The two routes head east up Box Elder Canyon in the southern Wellsville Mountains , finally leaving the valley of the Great Salt Lake into a small valley that contains Mantua Reservoir ( elevation 5200 feet / 1585 m ) . US @-@ 89 / US @-@ 91 turns north there , bypassing the town of Mantua to the west , and continues to ascend through Dry Canyon to Sardine Summit ( elevation 5900 feet / 1798 m ) . Another small valley leads to Wellsville Canyon , where the four @-@ lane roadway again turns east and descends into the Cache Valley . In that valley , US @-@ 89 / US @-@ 91 heads northeast , bypassing Wellsville to the east , into downtown Logan . US @-@ 91 continues northerly from Logan into Idaho , but US @-@ 89 splits to the east , beginning a long climb of the Bear River Range through Logan Canyon . The Logan Canyon Scenic Byway , a Utah and National Scenic Byway , begins at Logan and follows US @-@ 89 up the canyon , past the access road to the Beaver Mountain ski area , to Garden City and on to the state line . Bear Lake Summit ( elevation 7800 ft / <unk> m ) , at the top of the range , is the highest point on US @-@ 89 in Utah , from which it descends the east slope via horseshoe curves to Garden City on the shore of Bear Lake ( elevation 5900 ft / 1798 m ) . The final segment of US @-@ 89 to the Idaho state line follows the lake 's west shore , its location constrained by the Bear River Range just to the west . 
