The Nisga'a Final Agreement, also known as the Nisga'a Treaty, is a treaty settled between the Nisg̱a'a, the government of British Columbia, and the Government of Canada. As part of the settlement in the Nass River valley nearly 2,000 square kilometres of land was officially recognized as Nisg̱a'a, and a 300,000 cubic decameter water reservation was also created. The Bear Glacier Provincial Park was also created as a result of this agreement. The land-claim settlement was the first formal treaty signed by a First Nation in British Columbia since Treaty 8 in 1899.
The agreement was signed on 27 May 1999 by Joseph Gosnell, Nelson Leeson and Edmond Wright of the Nisg̱a'a Nation and by Premier Glen Clark for the Province of British Columbia. Then Minister of Indian Affairs and Northern Development Jane Stewart signed the agreement for the Canadian federal government on 4 May 1999.
The constitutional legality of the Nisga'a Final Agreement was challenged by some Nisga'a under Laxsgiik chief James Robinson (Sga'nisim Sim'oogit) and Mercy Thomas, particularly the self-government and law-making powers of Nisga’a government. On October 19, 2011 the Supreme Court of British Columbia handed down its decision upholding the constitutional validity of the Nisga’a Final Agreement.