Weaselwords, your assumed name fits you very well. In most cases, the people that signed treaties were NOT the leaders chosen by the Indians, but were "leaders" chosen by the white man for their willingness to give away everything for a few coins.
The British Government, and the succeeding Canadian government were very able to find the Judas's among the natives that would sell out. They used them, got their signatures (or marks in many cases) and then almost immediately abrogated the treaty that had just been signed.
Name a single treaty that the government has ever honored completely?
The governments duplicity begins with the Jay Treaty (the one that ended the American Revolution). This treaty, and the one that ended the War of 1812, specifically spelled out the rights of Indians to move back and forth across the borders of Canada and the USA, to move their chattles, to seek employment, etc. without hinderance.
Canada refuses to honor those clauses. The USA still does. And Canadian Indian that is half blood or more, can move to the USA with all of their possessions, can get a Social Security Card and work, without ever going through INS or any other agency.
If an Indian attempts to do the same thing in Canada, they are subject to arrest, deportation and possibly even confinement. Any goods that they bring with them are either taxed horribly, or confiscated. The Supreme Court of Canada has ruled that the clauses of those treaties have no legal meaning what so ever.
(By the reasoning of the Supreme Court, a State of War still exists between the USA and Canada by the way.)