Sand Island is an island in Baker Bay in the mouth of the Columbia River, located in Clatsop County, Oregon. It is situated north of Fort Stevens State Park and the Clatsop Spit, east of Cape Disappointment, and just south of Ilwaco, Washington. Sand Island is also the northernmost point in the state of Oregon.
Sand Island is physically situated closer to the Washington mainland than to the Oregon mainland, although the border between the two states traverses the Columbia River north of the island. It often changes position in the river, and was described by Captain George Vancouver during his expedition but not by Lewis and Clark. The island was formerly subject to a border dispute between Oregon and Washington; Oregon won possession in a 1908 Supreme Court case, Washington v. Oregon.
According to an 1889 description in the Coast Pilot of California, Oregon, and Washington:
The island is covered in grass with a few small trees towards the center. East Sand Island, located nearby, is smaller and is home to thousands of nesting birds, who mostly avoid the larger Sand Island.