The Torah records the passing of all the patriarchs and matriarchs:
Sarah - Bereishis 23:1-2
Avraham - Bereishis 25:8-9
Rochel - Bereishis 35:19
Yitzchak - Bereishis 35:29
Then Rivkah is not mentioned explicitly, but Rashi explains that this is not recorded in order so that people would not curse her as the mother of Esav. But nonetheless it is still alluded to in Bereishit 35:8.
The only mention I have found is in Bereshis 49:31, where Jacob mentions that he buried Leah in Ma'aras Ha'Machpela.
So why does the Torah not mention her passing like it does the rest of the Avos and Emahos?