In Operation Mountain Viper, the United States Army and the Afghan National Army (nearly 1000 in number) worked together from August 30 to early September, 2003, to uncover hundreds of suspected Taliban rebels dug into the mountains of Daychopan district , Zabul province, Afghanistan.

The Operation killed an estimated 124 militants. Five Afghan Army personnel were killed and seven were injured. One U.S. soldier died in an accidental fall.

The Operation worked in conjunction with Operation Warrior Sweep.