Fig. 2.

Bulk δ¹³C and δ¹⁵N values from hearths in component 1 (yellow circle), component 2 (orange circle), and component 3 (dark circle) from USR site. (A) Distribution of δ¹⁵N values of components 1, 2, and and 3 in USR hearths and reference samples. (B) Animal muscles from Alaska in literature (28–36), from modern interior Alaska (in this study), and bone collagen from USR fauna (in this study), and other ancient salmon in Alaska (23, 37–39). AB, aquatic bird (red square); FF, freshwater fish (blue square); SA, salmon (pink square); TA, terrestrial animals (green square).