The Diamondbacks have trained at Tucson Electric Park since the team's inception, but the decision by the White Sox to move operations to a Glendale facility triggers an out clause in the team's lease with Pima County, giving them freedom to move should there be only two teams remaining in Tucson. The Colorado Rockies have the same clause in their lease for Hi Corbett Field (which is slated to end in 2011 anyway), and in the past year Rockies officials have openly discussed a spring move to Phoenix as well.
The Gila River Indian Reservation is located in Chandler, in souther Maricopa County. Tribal officials have been working on a privately financed two-team spring-training complex that could open as soon as 2011. Tribal officials have been talking with the Diamondbacks and the Rockies as well as the Baltimore Orioles; meanwhile, the Milwaukee Brewers have also been quietly exploring options to Maryvale Baseball Park, where the team's lease expired in 2012.