The religious vocabulary of the Andes is Quechua vocabulary, and much of what is known about pre-conquest Andean religion comes from documents written in Quechua or compiled by people working in it. A huaca is a sacred thing or place, which might be a mountain, a spring, a stone, a mummified ancestor or a shrine; an apu is a mountain lord; pachamama names the earth. These are not archaic terms. Offerings to apus and to pachamama continue across the Andes, alongside and inside Catholic practice, and the relationship between the two is a matter for the communities concerned rather than for an outside verdict about syncretism.
The written record has an uncomfortable shape. Much of it was produced during the extirpation of idolatry campaigns of the seventeenth century, in which ecclesiastical officials investigated and destroyed local shrines and recorded in detail what they were destroying. The Huarochiri Manuscript, the single most important source for Andean mythology, is a Quechua text compiled in that context. As with the Nahuatl material, the provenance does not make the content false and it does have to travel with it, because the questions asked shaped the answers written down.