Central Government Act
Section 3 in The Bihar Reorganisation Act, 2000
3. Formation of Jharkhand State.- On and from the appointed day, there shall be formed a new State to be known as the State of Jharkhand comprising the following territories of the existing State of Bihar, namely:- Bokaro, Chatra, Deogarh, Dhanbad, Dumka, Garhwa, Giridih, Godda, Gumla, Hazaribagh, Kodarma, Lohardaga, Pakur, Palamau, Ranchi, Sahebganj, Singhbhum (East) and Singhbhum (West) districts; and thereupon the said territories shall cease to form part of the existing State of Bihar.