Map of counties in the Qinghai-Gansu (or Gansu-Qinghai, or Amdo) sprachbund.
Own work

County boundaries from China Data Lab, 2020, "China County Map with 2000–2010 Population Census Data", doi:10.7910/DVN/VKGEBX, Harvard Dataverse, V1
National noundaries from Natural Earth 1:110m Cultural Vectors
Conversion to SVG using svgis
Kanguole