[2] The route is an entirely undivided surface highway that passes through rich cotton country.

[3][4][5][6] AR 90 begins at Main Street in Ravenden and heads north to cross US 62/US 63/US 412.

The route runs diagonally northeast until meeting AR 135 east of Knobel.

The route runs east to meet AR 141 near Boydsville, Arkansas and US 49/AR 1 in Rector.

AR 90 continues west to terminate at Route 84 at the St. Francis River on the Missouri state line.