Where does “Lapahie” come from?

Lapahie (Navajo) comes from Navajo łibá, from Navajo łi-, from Navajo -ł-, from Proto-Athabaskan ɬ.

Ancestry of “Lapahie”, step by step

Step	Language	Word	Meaning
1	Navajo	łibá	it is gray
2	Navajo	łi-	An adjectival prefix that forms neuter imperfective verbs, especially those relating to color
3	Navajo	-ł-	The -ł- classifier or valence-change prefix, a...
4	Proto-Athabaskan	ɬ	—