in 2004, "measure z" was passed by the voters (73%) in fresno to raise money to expand the zoo, and to improve the animal exhibits. the us$150 million project was contingent upon the submission and review of an environmental impact report. the name of the zoo was shortened to fresno chaffee zoo in 2006. in 2007, a traveling "stingray bay" exhibit visited and attracted large crowds. several stingrays were bred while they were visiting fresno. in 2009, a permanent stingray bay exhibit was opened, funded by measure z. in the rain forest exhibit, the former butterfly house (maddis house) reopened as the tropical treasures exhibit in march 2009, with poison dart frogs and a sloth among other species.