For the entire length, SR 174 is named Fort Knox Road.

The entire route is in Prospect, Waldo County.

It heads east descending a small hill and crosses a railroad and marshland containing Carley Brook (just south of the South Branch Marsh River confluence).

SR 174 now begins to closely parallel the Penobscot River, but at a higher elevation than the water surface.

After passing a small parking area that was the former approach to the Waldo–Hancock Bridge, SR 174 ends at a signalized intersection with US 1/SR 3 at the western approach of the Penobscot Narrows Bridge.