The treaty of 1655, prohibiting the Montauk from selling their remaining lands to anyone but East Hampton, first established Wyandance as the "chief sachem of Long Island" to facilitate land transfers as far west as Huntington. Complaints from Sachems and settlers there led Governor Nicolls to declare the title void in 1665.

The 1660 deed, negotiated when the Montauk were weakened by disease, raids from the Narraganset, and the loss of Wyandance, sold the Montauk peninsula from Napeague to the point for 100 pounds sterling (or equivalent in wampum or corn) to be paid 10 pounds a year for 10 years. Residence rights on the peninsula were returned to the Montauk in the deed of 1687 with the newly-formed Trustees of the Freeholders and Commonality of Easthampton. As late as 1702 the Montauk were still complaining they had not been paid this fee.

The Montauk then began to sell land to Rip Van Dam, a wealthy merchant of New York; the alarmed Trustees quickly negotiated four separate documents in 1702 which set a "reservation" boundary, regulated grazing rights, allowed the Montauk to move back and forth between the eastern and western sides of Great Pond (Lake Montauk), but not both sides simultaneously, and banned sale of hay by the Montauk and limited the amount of livestock they could raise. These limitations effectively prevented the growth of the Montauk population.

In 1719 the Trustees required a 100 pound bond of the Montauk to prohibit any Native Americans other than Montauk to live there. The population dropped to about 160 people by the 1740s. In 1754 the Montauk agreed to a further provision that no "mustees or mulattos" would be allowed to live at Montauk, further limiting the group's size, to hasten their demise. By 1794 the Montauk were prohibited by the Trustees to graze horses which were not their own - another sanction to reduce economic viability. A census of the Montauk was sent to the Long Island Assemblymen in Albany to prove they were "true blooded natives" in 1806 - to forestall eviction?

A Petition to the New York Assembly in 1800 by Benjamin and Stephen Pharaoh explains why the Montauk appeared to accept these repressive measures: "...the war being ended between us and the Narowganset tribe, we demanded the deeds, but they would not give them up, but said they would let us improve at certain seasons of the year a certain part of the land as by a lease - which we being the weaker party was obliged to consent..."

How quickly the Montauk became attached to European trade goods is revealed by objects found at the turn of the century in a 17th and early 18th century burial ground at Pantigo. Among the wide range of export wares was a late 17th century glass bottle with the name 'Wobetom' carved on it - a material link with this period, as Wobetom put his symbol on several of the deeds alienating the Montauk land. Eighty percent of the Natives signing the deeds used their personal symbol, the remainder signed an 'X'.