SR 187 begins at an intersection with SR 658 (Winterville Road) in the village of Guilford. The state highway heads east as two-lane undivided Guilford Road to the town of Bloxom. SR 187 veers north along Shore Main Drive, then heads east again to intersect the northern end of SR 316 (Bayside Drive) and cross an inactive railroad line.
SR 187 starts at a junction with SR 658 in Guilford, travels eastward on two-lane undivided Guilford Road to Bloxom, then turns north along Shore Main Drive before heading east again to intersect the northern end of SR 316 and cross an inactive railroad line.