It runs from U.S. Route 52 (US 52) and US 281 in Jamestown to the Canada–United States border near Sarles.

ND 20 then continues northwest for 28.3 miles, passing by Warrick and Tokio before reaching the northern terminus of ND 57 and turning north again.

The intersection is located on a causeway of Devils Lake.

ND 20 comes across a brief concurrency with ND 66, and passes west of Munich before turning onto ND 5 for 5.8 miles.

ND 20 spends its last 14.5 miles traversing rural areas, with the last important population center along the highway being in Calvin.