Why the shapes are approximate

The cession shapes are drawings of drawings, and they are not legal boundaries.

Charles C. Royce drew his maps in the 1890s at about 1:2,000,000, often from treaty descriptions that named rivers, landmarks and survey lines that have since moved or vanished. In 2017 the US Forest Service georeferenced those maps. We simplify the result slightly for the web. Every step adds error, and no step was checked against the treaty texts.

• Cession outlines are dashed to show they are approximate.
• Seven of Royce’s 724 cessions have no shape in the Forest Service layer; they appear in lists and on their own pages.
• Royce recorded what the government treated as ceded. The shapes do not show any nation’s homeland, and overlapping cessions often reflect overlapping claims.
• The map stops zooming in at a scale the sources can support, and the site never looks up addresses or parcels.
• Today’s reservation and trust-land boundaries come from the US Census Bureau. They are statistical, not legal, descriptions.