Contractor Kiewit Building Group has been selected by the Denver Zoo from a field of five bidders to build the $50 million, 10-acre Asian Tropics exhibit. When complete, in 2011, the exhibit---which will house elephants, rhinos, and myriad other animals---will be the largest in the zoo's 113-year history, notes the Denver Business Journal . Kiewit, of Omaha, Nebraska, built the zoo's Bird Propagation Center in 2007. A groundbreaking ceremony featuring Mayor John Hickenlooper, zoo President/CEO Craig Piper, and others is scheduled for tomorrow. Many of the diverse animals that will be included in Asian Tropics are highly endangered, according to the zoo . Currently, the zoo is showing off Kai, a hyena, born on the grounds in August (via 9News ).