What do 'Klondike' and 'Yukon' mean in the Athabaskan language?

KLONDIKE. This region of northwest Canada, famous for its former rich gold deposits, takes its name from the river Klondike. The river's name is said to derive from an Indian word meaning 'river of fish.'

YUKON. The territory of northwest Canada takes its name from the river Yukon, whose own name represents the Indian yu-kun-ah ('big river').

Taken from Brewer's Dictionary of Names

Don't know about Athabaskan but Klondike is from throndik meaning 'river of fish' and Yukon is from yu-kun-ah meaning 'big river'. Brewer's Dictionary of Names etc.

"The Klondike River is a tributary of the Yukon River in Canada that gave its name to the Klondike Gold Rush. The Klondike River has its source in the Ogilvie Mountains and flows into the Yukon River at Dawson City.

Its name comes from the Hän word Tr'ondëk (/???ont?k/) meaning hammerstone, which were used to hammer down stakes used to set salmon nets." - https://en.wikipedia.org/wiki/Klondike_River

"The Russians named the Yukon River, believing that "yuk-khana" was a Deg Xinag phrase meaning big river.[6] However, "yuk-khana" is not a Deg Xinag phrase meaning big river.[7] Probably, the Deg Hit'an borrowed the name from an upriver language and borrowed the "big river" meaning from the Central Yup'ik name.[8] Most likely, Yukon was derived from an obsolete Gwich'in word,[9] which included the concept of long water or wide water, but did not mean "big" river or "great" river." - https://en.wikipedia.org/wiki/Yukon_River

"Gwich'in is a member of the Northern Athabaskan subgroup of the Athabaskan language family, in greater the Na-Dene family of languages. It shares the Han-Kutchin subdivision with the Hän language." - https://en.wikipedia.org/wiki/Gwich%CA%BCin