This article explores how the “governmental parks” (seifuritsu kōen) established by the Government of the Ryukyu Islands (GRI), a subordinate administrative body in Okinawa under the U.S. administration authorities, were transformed into Japanese national parks and quasi-national parks as part of the reversion of Okinawa to Japan. In doing so, it examines how the issues of nature management and utilization were discussed within the context of the Okinawa reversion. Three historical and coastal scenic areas were designated in October 1965 as Okinawa Coastal Governmental Park, Okinawa Battlefield Governmental Park, and Yokatsu Marine Governmental Park, respectively, based on the GRI’s Governmental Park Act of 1957. These governmental parks were established with the goal of developing the local economy by promoting tourism, while at the same time preventing overdevelopment and preserving the natural environment. With the exception of Yokatsu, which was de-designated in 1972 to make way for the construction of oil refinery and storage facilities (Central Terminal Station) prior to the reversion, the other two were re-designated as Japanese quasi-national parks. On Iriomote Island in southwestern Okinawa, Iriomote Governmental Park was established shortly before the reversion for its subtropical landscape and ecological value, and then reorganized into Iriomote National Park (the predecessor of the current Iriomote Ishigaki National Park) upon the reversion. These processes provide concrete examples of the interactions between international conservation networks, the central government, local authorities, and local residents within the context of the “integration” between Okinawa and mainland Japan, which began in earnest in the late 1960s. As the Japanese government’s perspective differed from the intentions and practices of Okinawan local authorities and residents according to their own interests and agendas, this article pays particular attention to the “mismatches” between the various actors over development and nature conservation.