The building was renovated in 1979 through efforts of the Green River Bicentennial Commission and the Expedition Island Pavillion Restoration Committee at a cost of $256,412.

The island has been known by various names since it was originally claimed by S.I. Field when he platted Green River City in early 1868. It was known as the Island, Johnson Island, Island Park and Expedition Island. It had been in private ownership until Green River City purchased it in October 1909. The Island Park’s name was changed to Expedition Island on May 24, 1969.

In 1949, a plaque was placed on the island by the Historical Landmark Commission of Wyoming “Marking the spot from which Major Weslely Powell and party departed May 24, 1869, to make first exploration of Green and Colorado Rivers, arriving mouth of Grand Canyon Aug. 29, 1869.”

On April 16, 1969, Expedition Island was designated a Registered National Historic Landmark by the U.S. Department of the Interior National Park Service, indicated that “This site possesses exceptional value in commemorating or illustrating the history of the United States.”