The Royce Maps are historical maps of American Indian territory that the native nations ceded to the United States or was reserved by the native nations between 1784 and 1894. They were published along with a table that gives information about the treaty that ceded or reserved the land including when and where the treaty was concluded and a citation to find the treaty. It's incredible information, but quite fussy to use. The easiest way to make sense of the information is to use the "Schedule of Indian Land Cessions" table together with the maps.
The Schedule of Indian Land Cessions comprises 709 entries and "indicates the number and location of each cession by or reservation for the Indian tribes from the organization of the Federal Government to and including 1894, together with descriptions of the tracts so ceded or reserved, the date of the treaty, law or executive order governing the same, the name of the tribe or tribes affected thereby, and historical data and references bearing thereon."
For help making sense of all of the treaties and movements that a particular tribe made, you maybe find it helpful to consult the Encyclopedia of American Indian Removal (available online). Its narratives can help stitch things together and make sense of how different things relate.
Go to the Library of Congress site. Click "browse by tribe." Look for your tribe on the list. There may be several entries as each slightly different group or sub-group of people will merit an entry. When you click into the tribe, it will bring up pages from the Schedule of Indian Land Cessions. This will give information about the treaty and a cession map number telling you where on the Royce Maps that area appears. You can use the Royce Maps by State Site to see a single state's map or go to the Forest Service Site, filter by cession number, and find the area on the map where the number appears. This approach may be helpful where the geographic area spans more than one state.
The best way to deal with this situation is to look at your treaty and take note of the name(s) of the tribe and the date the treaty was signed. From there, you can go to the Library of Congress site and select browse by date. You can also look up the tribe as described above and pick the entry that corresponds with the correct date.
NOTE: The Library of Congress site is an archived version of a very helpful site that no longer exists. Some parts of the site may not have been archived. If you run into a dead link, especially after you click on the name of a tribe, write down the page ranges from the Serial Set and look them up in the Schedule of Indian Cessions PDF.
Go to the U.S. Forest Service site. Search by location. Look at the cession map numbers on and near your location. Go to the left side of the screen and click the little funnel icon to filter. Enter one of those cession map numbers. Click the table icon to "show table." The table will give you information about the treaty that covers that cession map area. It will give you links to the Schedule of Indian Land Cessions and a link to the full text of the treaty.
For a very comprehensive look at the history of tribes in what is now the state of Arizona, see Appendix A to the University of Arizona's report, University of Arizona Land-Grant Project: Tracking the History of Land-Grant Enrichment at the University of Arizona. It details what the Royce maps and treaties say about tribes in Arizona with a comprehensive timeline for each.
You could start with the treaty with the Six Nations of New York signed on October 22, 1784. Looking it up by date on the Library of Congress site brings you to this page. Here are the two corresponding pages from the Schedule of Indian Land Cessions:
Reading the column headings from left to right, this table tells you the date on which the treaty was concluded, where it was signed, a citation to the treaty that will allow you to find the full treaty text, the name of the tribe or tribes that signed the treaty with the United States, a brief description of what the treaty did, an exhaustive description of the land, designations to help you use the Royce maps: a Royce map number and the state in which the territory is found. Thus, the first entry that we read in this schedule is a treaty between the Six Nations of New York and the US in 1784. It then mentions Royce map number 1 and says it was in Pennsylvania. If you go to the Royce Map Images site and bring up Pennsylvania, you'll see a green area on the map marked with the number 1. That area shows you what the description of the land in the treaty looks like on an actual map:
The Schedule of Indian Cessions also mentions the state of New York and refers simply to a dotted black line rather than a number. We can see on the map of Pennsylvania that there is a great line extending north from the northwest corner of the state right around Lake Erie. If we pull up the map for New York on the Royce Maps by State site, we see this map:
Note the dotted black line right around the town of Little Valley, New York. If you zoom in (and the version of this image on the Royce Maps by State site is much bigger), you see that it reads "West Boundary of the Six Nations as defined by state of N.Y. by treaties of October 22, 1784 and January 9, 1789 with the United States."