Numbers 33:36-38

36 They set out from Ezion-geber and camped in the wilderness of Zin (that is, Kadesh).
37 They set out from Kadesh and camped at Mount Hor, on the edge of the land of Edom.
38 Aaron the priest went up Mount Hor at the command of the Lord and died there in the fortieth year after the Israelites had come out of the land of Egypt, on the first day of the fifth month.