The suspects are among 65 people whose charges have been unsealed in White Plains.
U.S. Attorney Preet Bharara says the Elm Street Wolves and the Cliff Street Gangsters dealt cocaine and marijuana in downtown Yonkers for the last decade.
He says their territories were just a few blocks apart and sometimes they worked together, using weapons to enforce their trade.
Most are charged with drug and weapons crimes that carry mandatory sentences of 10 years in prison. Three are charged with killing a rival.
Of the 65 indicted, 63 had been arrested by late afternoon.
The Yonkers police commissioner says there will be an immediate positive effect in the neighborhood.