Call ahead to the tribal government office to understand if and where visitors are welcome. This way, you can avoid any unexpected common travel mishaps on your journey. When visiting any reservation, you are considered a guest and should respect the privacy of the people who live there and follow the local laws.
Money for tribe's come in a couple different ways; dividends or gambling revenues. Dividends can come from the government to be distributed to tribes and their members based on the tribes history with government. They can receive compensation for land disputes or things like land rights.