Gaming on this stretch of desert belongs to a nation whose lands cover 2.8 million acres - the second-largest tribal land base in the United States. Desert Diamond Casino at 1100 West Pima Mine Road, off Interstate 19 in Sahuarita south of Tucson, opened in 2002 as the flagship expansion of the Tohono O'odham Nation's gaming enterprise. The Nation's modern gaming history began with Papago Bingo in 1983; its first compact with Arizona in 1993 turned that hall into the original Desert Diamond Casi.....