Montana

I-94 begins at Billings and travels northeastward toward Glendive before exiting the state to the east. I-94 links seven counties, which are Yellowstone, Treasure, Rosebud, Custer, Prairie, Dawson, and Wibaux counties and passes near or through Miles City and Glendive while connecting with I-90 in Billings. The highway is notable for following the Yellowstone River from Billings through Glendive. Beyond the western terminus of I-94, I-90 connects westbound I-94 travelers to points west such as Butte; Missoula; Coeur d'Alene, Idaho; Spokane, Washington; and Seattle, Washington.

North Dakota

The route enters at Beach and passes through the Badlands near Medora (near the Theodore Roosevelt National Park South Unit). A public rest area about seven miles (11 km) east of Medora provides an awe-inspiring view, especially at sunset, and an opportunity to hike through some of the scenery on the Painted Canyon Trail. Further east, I-94 provides access to the North Unit of Theodore Roosevelt National Park, then passes through the cities of Dickinson, Mandan, Bismarck, Jamestown, and Valley City on the way to West Fargo and Fargo, where it leaves the state and crosses into Minnesota. Throughout the state, the route generally travels relatively straight east and west following both the railroad route and the former route of US Route 10 (US 10, called "The Old Red Trail") where its western terminus is at exit 343 in West Fargo.

The highway intersects with the Enchanted Highway 11 miles (18 km) east of Dickinson at exit 72. At New Salem, it passes Salem Sue, a 38-foot-high (12 m) sculpture of a Holstein cow and is clearly visible from I-94 on the south side of the road. A drive up the road to Sue will take visitors to a vantage point where they can see a panoramic landscape for many miles. Between Mandan and Bismarck, I-94 crosses the Missouri River with a view of the Northern Pacific/BNSF Railway Bridge on the south side of the road. At Steele, it passes the world's largest sculpture of a sandhill crane (named Sandy), which is 40 feet (12 m) tall and visible from I-94 on the south side of the road, just to the east of exit 200. At Jamestown, it passes the world's largest sculpture of the buffalo (actually bison) named "Dakota Thunder", which is 28 feet (8.5 m) tall and is visible from I-94 on the north side of the road. US 52 is concurrent with I-94 from Jamestown to the Minnesota state line. approximately milemarker 275 on the westbound lanes between Jamestown and Valley City, there is a small green sign marking the Laurentian Divide, which marks a continental divide where rivers south of the divide drain into the Gulf of Mexico, while the rivers north flow into the Arctic Ocean. The highway reaches Fargo, before the Red River.

Minnesota

Leaving Fargo and entering Moorhead, Minnesota, I-94/US 52 crosses the Red River. East of Moorhead Municipal Airport, the Interstate travels in a northwest–southeast trajectory past Fergus Falls, Alexandria, and St. Cloud on the way to the Twin Cities and eastward out of the state.

The road crosses the Mississippi River in Minneapolis between the Prospect Park and Seward neighborhoods. As it crosses over the only true gorge along the Mississippi's entire 2,350-mile (3,780 km) length, where steep bluffs extend to the waterline.^[2] The highway joins Minneapolis and Saint Paul together where it meets Minnesota State Highway 280 (MN 280). US 52 leaves I-94 after running concurrently with I-94 from the North Dakota state line and heads southbound toward Rochester. In the Twin Cities, the routing of the highway is politically charged, primarily through many historic working-class and Black neighborhoods.^[3][4] In Saint Paul, the routing of I-94 is set through and displaces the historic Rondo neighborhood, which prior to the highway construction was the largest Black community in Saint Paul.^[5][6][4]

East of Saint Paul, I-94 leaves Minnesota between Lakeland, Minnesota, and Hudson, Wisconsin, while crossing the St. Croix River.

Wisconsin

I-94 enters Wisconsin east of the Twin Cities at Hudson. It traverses the hilly terrain of northwest Wisconsin, crossing the Red Cedar River near Menomonie. East of Menomonie, I-94 junctions with WIS 29, a major East–West expressway connecting I-94 with Wausau, and Green Bay. It then passes Eau Claire before turning southeastward and joining with I-90 in Tomah. Southeast of Tomah, the highway passes the major tourist area of Wisconsin Dells. Here, vacationers can find a multitude of water parks, camping, amusement parks, zoos, river excursions, as well as lodging and shopping. Further southeast, I-94 joins up with I-39 in Portage at the base of Cascade Mountain, a popular ski area. Just south of Cascade Mountain, I-94 crosses over the Wisconsin River. I-94 leaves I-90 and I-39 east of the state capitol of Madison and resumes its easterly path toward Milwaukee. I-94 weaves its way into Downtown Milwaukee before turning south and heading to Chicago, entering Illinois at Pleasant Prairie.

Illinois

In the state of Illinois, I-94 runs south from Wisconsin to Indiana via downtown Chicago. It is tolled on the Tri-State Tollway to the I-94/I-294 split; it then runs east to the Edens Expressway, where it soon joins again with I-90 on the Kennedy Expressway and turns south through the city of Chicago. I-90 leaves south of downtown Chicago to the Chicago Skyway. At I-80, I-94 runs east to Indiana on the Kingery Expressway.

Indiana

In the state of Indiana, I-94 runs east from Illinois concurrently with I-80. It crosses I-90 (Indiana Toll Road), where I-80 joins I-90 east toward Ohio. I-94 continues northeasterly, paralleling the Lake Michigan shoreline into Michigan. The 55-mile-per-hour (89 km/h) speed limit used to continue east of exit 26; now it ends a mile (1.6 km) east of I-80/I-90, where the speed limit goes up to 70 mph (110 km/h) on eastbound I-94.^[7] Between milemarkers 0.0 and 15.5, the highway is also posted along with I-80. Between milemarkers 15.6 and 19.0, I-94 is posted alone.

Michigan

I-94 runs north along Lake Michigan to St. Joseph and Benton Harbor before heading east toward Detroit. It turns northeast to Port Huron where it meets I-69 and ends at the Blue Water Bridge, where it becomes Ontario Highway 402 in Point Edward, Ontario.