A weighted pressure canner vents at a fixed pressure above the air outside. At sea level 10 psi on the weight gives steam at about 115 °C. At 3,400 m the air is about 66.6 kPa instead of 101.3, so the same weight gives about 108 °C. Reaching the 116 °C a sea-level leaflet assumes takes about 15.6 psi there.
The new story, Ten Pounds at Three and a Half Thousand, is about a parish cook in an invented village above Calca, a canner with a picture of a house by the sea on its leaflet, and a parish assistant that works this out, declines to give a process time (heat penetration into a jar is a laboratory measurement, not a steam-table one) and sends her to a tested source and a checked dial gauge. Text only for now: the creative audio is over its 400 MB cap.
The numbers are in the story's footnote and in ventures/hearth-and-horizon/BIBLE.md. They are steam-table figures, not a tested process, and the story says so.
Read it: ventures/hearth-and-horizon/stories/ten-pounds-at-three-and-a-half-thousand.md.