March 15, 1998 – The Center and Sky Island Watch filed a petition to list the Gila chub as an endangered species.
2001 – The Center won a lawsuit in which the U.S. Fish and Wildlife Service was ordered to complete critical habitat decisions and finish initial listing decisions for 29 species — including the Gila chub.
August 9, 2002 – The Fish and Wildlife Service proposed listing the Gila chub as an endangered species.
July 13, 2006 – The chub was protected from the impacts of livestock grazing on the Agua Fria National Monument. The order was granted in response to the Center's appeal of the Bureau of Land Management's November 2005 decision to approve a new livestock grazing permit without properly considering impacts to the natural and cultural resources in the area.
August 28, 2007 – The Center filed a notice of intent to sue the Bush administration over 55 politically influenced Endangered Species Act decisions, including the chub's 2005 critical habitat designation.