Between Folkston and Kingsland, the highway crosses several streams that feed into the parallel St. Marys River. SR 40 enters Kingsland on King Avenue, which has a grade crossing of the First Coast Railroad and intersects US 17/SR 25 (Lee Street). Here, the state highway expands to a four-lane undivided street.
Between Folkston and Kingsland, the highway traverses several streams that flow into the St. Marys River. SR 40 enters Kingsland on King Avenue, which has a railroad crossing with the First Coast Railroad and intersects US 17/SR 25 (Lee Street). The state highway then expands to four lanes in this area.