The arena is home to the Denver Nuggets of the National Basketball Association ( NBA ) , the Colorado Avalanche of the National Hockey League ( NHL ) , and the Colorado Mammoth of the National Lacrosse League .
The arena opened on October 1 , 1999 , and is the current home to the Colorado Avalanche of the National Hockey League ( NHL ) , the Denver Nuggets of the National Basketball Association ( NBA ) and the Colorado Mammoth of the National Lacrosse League ( NLL ) .