Miller Rocks is on the Columbia River above The Dalles Dam near the Town of Biggs (OR), and is owned and managed by the State of Washington. Miller Rocks is a cluster of small basaltic islets just upstream of the larger main island (Miller Island). These islets support a large mixed species colony of nesting gulls. Currently, there is a large California gull colony (ca. 4,000 breeding pairs) and a smaller ring-billed gull colony (ca. 560 breeding pairs) on Miller Rocks. Some of the gulls that nest on Miller Rocks commute over 10 miles either up-river or down-river to forage on juvenile salmonids in the tailraces of the John Day Dam and The Dalles Dam, respectively. Both Caspian terns and double-crested cormorants have attempted to nest on Miller Rocks in the past, 17 breeding pairs of Caspian terns in 2001 and 5 breeding pairs of double-crested cormorants in 2006. Neither species attempted to nest there in 2007-2009.
