[Right Wing Professor]

Well, I'm not lawyer, but I did find the text of the 1838 Buffalo Creek treaty between the New York tribes and the United States.

http://tuscaroras.com/jtwigle/pages/treatyof1838.shtml

And it seems to me, under the text of the treaty, that the New York tribes agreed to be removed from New York to Indian territory. So I'm wondering how come there are any tribal lands left in New York state?

[Chad Fairbanks]

Well, it could be because the Tuscaroras are a different tribe than the others - so the treaty/agreement between tehm and the feds has zero impact on negotiations with other tribes.

[Right Wing Professor]

Following up.

http://college.hmco.com/history/readerscomp/naind/html/na_035300_seneca.htm

Efforts to remove Senecas from their lands culminated in the Treaty of Buffalo Creek in 1838, by the terms of which the four remaining Seneca reservations—Buffalo Creek, Tonawanda, Cattaraugus, and Allegany—were sold and provisions were made for the Senecas to remove to Kansas. The corrupt proceedings were protested, however, and a new Treaty of Buffalo Creek was signed in 1842. The new agreement stipulated the sale of Buffalo Creek and Tonawanda, but retained Allegany and Cattaraugus. As a result of the Buffalo Creek treaties, some Senecas moved to Kansas. Most did not, however, and of those who did, all but two returned.

Senecas of Tonawanda, who had not been present at the treaty proceedings in 1842, objected. By a treaty signed in 1857, they bought back most of their reservation with money set aside for their removal to Kansas. The Tonawanda Senecas maintain their government by hereditary chiefs, practice the Longhouse religion, perform traditional calendric rituals, and have medicine societies (a tradition separate from the Longhouse religion) for preventative and curative purposes

So translating this out of PC speak; they signed a treaty in 1838, broke it, signed another in 1842, broke that, and then some of them signed a third treaty allowing them to remain in New York.

[Arkinsaw]

Efforts to remove Senecas from their lands culminated in the Treaty of Buffalo Creek in 1838, by the terms of which the four remaining Seneca reservations—Buffalo Creek, Tonawanda, Cattaraugus, and Allegany—were sold and provisions were made for the Senecas to remove to Kansas. The corrupt proceedings were protested, however, and a new Treaty of Buffalo Creek was signed in 1842. The new agreement stipulated the sale of Buffalo Creek and Tonawanda, but retained Allegany and Cattaraugus. As a result of the Buffalo Creek treaties, some Senecas moved to Kansas. Most did not, however, and of those who did, all but two returned.

I found this, looks like the treaty was renegotiated in 1842 due to some sort of corruption and they ended up retaining two reservations in New York.

[Arkinsaw]

A bit more I found, appears to be some bribery and forgery involved to get a low-ball price is what scotched the 1838 treaty:
Land that was appraised for two million dollars was bought for two hundred and two thousand dollars, a deficit of slightly under 1.8 million dollars. Some chiefs were bribed to sign this land treaty, while other Chiefs' signatures were forged or not obtained at all.