Fig. 1

Maps of the study region at different scales. A General map showing the geographic settings of Hami in Xinjiang and the major routes of the Silk Road. (Base map downloaded from http://naturalearthdata.com) B Regional map showing the landscape around the Eastern Tianshan Mountains. C The entire drainage system of the BYRB, with all relevant archaeological sites marked (with legend at the bottom). Each site is labelled with a distinct identification number in accord with Table S1. D Zoomed in map of the upper–middle reaches of the BYRB to better distinguish the clusters of archaeological sites. (Satellite images sourced from: Esri, Maxar, Earthstar Geographics, and the GIS User Community.)