Thousand Islands level year-round, and support at least two living trees. The Thousand Islands archipelago is located at the outlet of Lake Ontario at the head of the Saint Lawrence River. The region is bisected by the Canada–United States border and covers portions of Jefferson and St. Lawrence counties in the U.S. state of New York, in addition to parts of the United Counties of Leeds and Grenville and Frontenac County in the Canadian province of Ontario. Geologically, most of the islands are located where a branch of the Canadian Shield runs south across the river to join with the Adirondacks. The
Thousand Islands (Cocoa Beach) Several areas of the Thousand Islands were filled but not fully developed, leaving large areas of uplands. During the late 1960s Brevard County Mosquito Control began dredging the Thousand Islands south of Minutemen Causeway, resulting in conversion of salt marsh to upland dredge spoil with the state-owned C-34 impoundment. Native wetlands are dominated by red, black, and white mangroves. Succulent marsh contains saltwort, annual glasswort, perennial glasswort, sea blight, and shoreline seapurslane. The transition zone between salt marsh and upland is dominated by bushy seaside oxeye ("Borrichia frutescens" (L.) DC.) and buttonwood ("Conocarpus erectus" L.). Transition areas dominated by graminoid