The [Samish] island is located on the estuary of the Samish River which enters Samish Bay and Alice Bay on the southeast side of the island.
Samish Island is generally considered part of the Nanaimo Formation. This formation is much younger than the other terranes in the San Juan Islands and consequently, is much less deformed.
The island is no longer an island. There is a Wikipedia article for the Samish Island, Washington unincorporated area, but not the island itself.