October 17, 1997 – The National Marine Fisheries Service listed southern steelhead as an endangered species, but arbitrarily excluded from the listing any steelhead found south of Malibu Creek, Los Angeles County, and upstream of several dams. The Service ignored its duty to designate critical habitat.
2000 – The Center and a coalition of fishing and environmental groups filed a lawsuit over the inadequate listing of the steelhead and failure to designate critical habitat.
May 1, 2002 – After steelhead were discovered in San Mateo Creek in 2002 and the Center threatened a second lawsuit, the Fisheries Service extended the steelhead's endangered listing into Los Angeles, Orange, and San Diego counties. Critical habitat protections were withdrawn when the Bush administration refused to defend the Service against a lawsuit brought by the National Association of Home Builders.
2004 – The Fisheries Service agreed to consider re-establishing the habitat protections after a lawsuit by a coalition of environmental and fishing groups, including the Center.
September 2, 2005 – The Fisheries Service designated approximately 673 miles of stream habitat as critical habitat for the Southern California steelhead.
December 23, 2005 – The Fisheries Service reaffirmed the endangered status of southern steelhead, but arbitrarily excluded resident and juvenile fish from the listed populations. The Service re-designated critical habitat, but reduced the proposed habitat protections by 80 percent and excluded important floodplain forests and habitat areas above dams.
June 2, 2016 – The Center and other conservation groups filed a lawsuit in federal court against United Water Conservation District over its operation of a dam that blocks runs of endangered steelhead on the Santa Clara River.