Located in the Kanawha River at South Charleston, this large island was surveyed at 65 acres when bought by the Union Carbide company in 1927. It is more than a mile long.

There is evidence that the island was inhabited in prehistoric times. In 1780, Fleming Cobb, a pioneer scout and settler of what would later become South Charleston, planted at least two pear trees on Blaine Island that survived until the 20th century. Cobb inherited the island from his uncle, Thomas Upton, in the early 1790s. It is said Cobb killed the last Indian slain in this part of West Virginia, near Blaine Island. He traded the entire island to Charles Blaine for a flintlock rifle. In later years the island served as the Blaine family farm, producing the finest watermelons in the valley.

In the early 20th century, Blaine Island held a small amusement park and bathing beach on the upper end, a favorite summer getaway for Charlestonians. Near the middle of the island a rudimentary airfield was cleared and aviators gave exhibitions. After its acquisition by Union Carbide the island served as a chemical plant of great importance. During World War II, its defense role merited a 24-hour U.S. Coast Guard Patrol circling the island. As of 2024, Carbide’s successor, Dow Chemical Company, had chemical operations on the island.