The signed section of MS 609 begins in Ocean Springs at an intersection with US 90, with the road continuing south into downtown.

MS 609 heads north along Washington Avenue as a four-lane undivided highway through a neighborhood before crossing the Fort Bayou Drawbridge over Old Fort Bayou into the neighboring community of Gulf Hills.

The highway passes by a golf course and through a mix of a business district and neighborhoods for several blocks before crossing Lemoyne Boulevard where it begins to straddle the border of St. Martin and Gulf Hills.

After crossing Bayou Costapia, the MS 609 officially resumes, but the highway is not signed as such and is not maintained by the state.

MS 609 finally leaves the forest and enters the small community of Vestry, where it comes to an end at an intersection with Vestry Road, roughly six miles (9.7 km) east of the Red Creek Off-Road ATV park and campground, as well as three miles (4.8 km) west of MS 57.