- Western Terminus:
- Rhode Island-Massachusetts state line
- Eastern Terminus:
- State Road (US 6) in Dartmouth
- 4.87 miles
MA 177 is a short extension of RI 177 into Massachusetts. It runs east for a few miles through Fall River, Westport, and Dartmouth to end at State Road (US 6). It has a grade-separated interchange with MA 88. The entire length is a two-lane undivided road with a few traffic lights.