Mount Pleasant's zone assignment — predominantly Zone B

Under the current zones, the Town of Mount Pleasant sits predominantly in Charleston County Zone B: Annex C lists "Areas in and around Mount Pleasant, James Island, and Johns Island" under Zone B, and "Areas north of Mount Pleasant between Zone A and US-17" also under Zone B. Zone A in the same document covers "Areas along the immediate coast to include. Sullivans Island, Isle of Palms, Dewees Island" and "Areas east of US-17 south to Buck Hall Recreation Area" — so land east of US-17 north of the Town toward Awendaw falls in Zone A, not B. Zone C covers "Areas between Highway 17 and the Charleston County line." The town-wide characterisation does not settle any individual address; SCEMD's stated method places boundaries on "natural features, roadways, popular landmarks," so a Mount Pleasant address can fall in A, B or C depending on location. Population figures published in Annex C for the county's zones (2025 estimates): Zone A 20,935 residents / 9,900 households; Zone B 202,105 / 88,291; Zone C 209,627 / 93,410. Checked 2026-09-04.