High Quality Content by WIKIPEDIA articles! Ocean Bluff and Brant Rock are two villages in the town of Marshfield in Plymouth County, Massachusetts, United States. The United States Census Bureau grouped the two villages together as a single "census-designated place" (CDP) for the purposes of the 2000 census; the CDP's population in that census was 5,100. Brant Rock and Ocean Bluff were originally inhabited by Native Americans, including members of the Wampanoag Tribe of the Algonquin nation. Native American artifacts have been found extensively in the area. The main road through the area, known today as "Ocean Street," is a Native American road, likely very ancient. The area at the end of Brant Rock village, known as Blackman's Point, was a Native American campground.