The entire road lies within the Rural Municipality of Piney and is 10 kilometres (6 miles) long.

PTH 89 begins at the Minnesota border, directly adjacent to the Piney Pinecreek Border Airport, with the road continuing south as Minnesota State Highway 89 towards Pinecreek and Roseau.

The highway heads north through rural farmland for several kilometers, crossing the Pine Creek Ditch (a flood diversion channel for Pine Creek).

It passes by a cemetery before traveling straight through the center of the community of Piney, with the highway serving as Main Street.

PTH 89 enters a wooded area as it has a junction with PR 201 before coming to an end at an intersection with PTH 12 (MOM's Way), with the road continuing north towards Badger as PR 203.