County Road 4 (sometimes referred to as Highway 4 or County 4), begins at the intersection of Central Entrance (MN 194) and Rice Lake Road in Duluth and continues north to its northern terminus at Biwabik in the Iron Range region of Minnesota.

The southern terminus of County 4 is at the intersection of Rice Lake Road / Mesaba Avenue and Central Entrance (MN 194) in Duluth.

The northern terminus of County 4 is at the intersection of Vermilion Trail and State Highway 135 (MN 135) in Biwabik.

The section of County 5 in Ness Township, south of Meadowlands, is unpaved gravel surface.

County 5 passes through the communities of: McCarthy Beach State Park is located on the route.

County Road 7 (sometimes referred to as Highway 7 or County 7), begins at the intersection of U.S. Highway 53 and Industrial Road in Grand Lake Township and continues north to its northern terminus at the city of Mountain Iron in the Mesabi Range region.

Aro was an Iron Range radio personality and entertainer whose best known song is "Highway No.

County 8 also has an intersection with State Highway 33 (MN 33) in Industrial Township near Independence.

County Road 9 is 11 miles (18 km) in length and passes through Canosia Township and the city of Rice Lake.

Midway Road serves as a key north–south arterial route along Duluth's western outskirts.

The southern terminus of County Road 13 is near its interchange with Interstate Highway 35 in Midway Township.

Its northern terminus is near its intersection with U.S. Highway 53 in the Pike Lake district of Canosia Township.

County Road 16 is 64 miles (103 km) in length and passes through the communities of Bengal, Forbes, Peary, Makinen, Fairbanks, and Bassett.

County Road 20 begins at its intersection with Vermilion Trail (CR 4), near Bass Lake west of Palo, the route heads west and then north into McKinley, and terminates at its intersection with Main Street in McKinley.

County 20 intersects State Highway 135 (MN 135) at McKinley, between Gilbert and Biwabik.

[2] County Road 23 is a route in the northern portion of the county, serving Nett Lake, the Nett Lake Indian Reservation, Orr, Leiding Township, Portage Township, and Buyck.

The 35.7 miles (57.5 km) route begins on Nett Lake Road in Nett Lake, heads east out of the Indian Reservation to Glendale, heads concurrently north with U.S. Highway 53 (Johnson Parkway) into Orr, heads east on Orr–Buyck Road out of Orr, and terminates at its intersection with Crane Lake Road (CR 24) in Buyck.

The central portion of the route is unpaved gravel surface from Buyck southbound towards Wakemup.

The route begins at the intersection of Zim Road (CR 27) and Fraser Road near Zim, generally heads north for 47.3 miles (76.1 km) into Cook, and terminates on Vermilion Drive at its intersection with 2nd Street Southeast (CR 24).

County 25 also passes near Buhl and Chisholm at its intersection with U.S. Highway 169 in Great Scott Township.

The 11.6 miles (18.7 km) route begins at the intersection of County Road 21 and Wahlsten Road near Embarrass, generally heads north and west through Wahlsten, and terminates at its intersection with State Highway 169 (MN 169).

At Stoney Brook Township, it slightly overlaps with U.S. Route 2 for 4/10 of a mile until it goes north through Brookston and curves east as Lamb Road.

County Road 32 is 2.5 miles (4.0 km) in length and passes through the communities of Hermantown and Duluth.

The southern terminus of County Road 48 is the intersection of Second Avenue and U.S. Highway 2 in the city of Proctor.

County Road 61 runs from the intersection of Congdon Boulevard and the Minnesota 61 Expressway near Brighton Beach in Duluth and follows the North Shore Scenic Drive to Two Harbors.

County Road 90 runs from the intersection of U.S. Highway 53 and Arlington Avenue in Duluth and continues north to its northern terminus at the intersection of Arlington Avenue and Arrowhead Road (CR 32) in Duluth.

County Road 91 is 6 miles (9.7 km) in length and passes through the communities of Duluth and Hermantown.

A $12 million reconstruction project of this section of roadway began in September 2012 and was completed in October 2013.

During the 2012–2013 reconstruction project, the roadway's notorious hairpin "horseshoe bend" section, as locals call it, on the 40th Avenue West segment of County Road 91, was straightened some, but could not be eliminated because of the steep nature of the hill, and the lack of additional funding that would have been required for an expensive project of blasting rock on the hillside.

County Road 303 runs from its southern terminus at its intersection with State Highway 169 (MN 169) and passes through the unincorporated area of Britt.