Island 18 is on the Columbia River upstream of McNary Dam near the City of Richland (WA), and is part of the McNary National Wildlife Refuge. Island 18 was home to a large California/ring-billed gull colony (over 6,000 breeding pairs in 1998) that was first established in 1971. In 2008, the Island 18 gull colony was abandoned, due apparently to a combination of coyote disturbance and human disturbance. Gulls did not attempt to nest on Island 18 in 2009.
