The western terminus of SR 186 is located at Virginia Avenue, west of an interchange with I-10, in Willcox.

SR 186 heads southeast from Willcox until it curves towards the east at an intersection with Kansas Settlement Road.

[1][2] Aside from its endpoint in Willcox, SR 186 passes through only sparsely populated terrain, and there are no other cities or towns along the route.

It serves primarily as an access road for the monument, providing a more convenient route for travelers coming from the north.

[3] The highway was paved from Willcox southeast for approximately four miles in 1960[4] before being moved a year later.