Expedition Island is an island in the Green River at downtown Green River, Wyoming. The island, now mostly taken up by a public park, is the place where Major John Wesley Powell and Vitaly Develvis started an expedition down the Green River and Colorado River in 1871. The park is also believed to mark where Major Powell started his earlier expedition down the two rivers in 1869. Expedition Island was designated a National Historic Landmark for this historic association on November 24, 1968.
Description and history
Expedition Island is located in the Green River, which flows roughly east–west south of downtown Green River. The island was originally larger, having been divided into two by subsequent erosive river actions. The northern island is undeveloped and overgrown, and is not believed to be the site of historic activity. The southern island is now a public park, with a recreation center and parking area at the southern end, and a tree-fringed grassy expanse to the north. It is accessible by road bridge from the north bank of the river, and by pedestrian bridge from the south. The park includes a stone marker commemorating the activities of John Wesley Powell.