What are the most populated or urban communities on Indian Reservations/First Nations

[xzmattzx]

What are the biggest and/or most urban towns and communities on Indian Reservations in the US, and First Nations in Canada?

It seems like reservations tend to be very rural, preserving the land as their ancestors used to see it, but the reality is that modern life is visible in some places on these reservations as well. Even in rural areas, of course, residents live in regular houses, and utilize modern businesses like gas stations or grocery stores. So human nature would tell us that there has been bigger congregations of people here and there on these reservations, even if they get overlooked.

I'm not sure if there is some place to see the largest municipalities actually on reservations (as opposed to not on reservations but having large Native populations) in each country.