Prior to incorporation as a city in 1955, the barrier island was home to four smaller towns – Sunset Beach from the southernmost end of the island to 97th Avenue; Boca Ciega from 98th to 103rd Avenue; Treasure Island from 14th Avenue to 118th Avenue, and Sunshine Beach from 119th Avenue to Johns Pass.
The mangrove islands of Isle of Palms and Isle of Capri were originally connected to the main island but the Great Gale of 1848 severed the connection. Paradise Island was purchased in order to build the Causeway in the 1930’s.
The Treasure Island Causeway Bridge opened to automotive traffic for the first time on Nov. 15, 1939. Before then, the only way to reach to island was by boat. Until the early 1970s, most of Treasure Island’s streets were made of sand and shell, but afterwards, annual paving projects took place through the mid-1970s.
Excerpts from "The Treasure Island Story", by Bonnie L. Williams (2003). Ms. Williams was formerly a City Clerk for the City of Treasure Island.