Natural Resources:
Mostly, minerals like gold, zinc, lead and silver are Yukons leading nonrenewable resources. Diffucult access to the minerals (because of rugged terrian)  have made it so that the mining industries haven't taken off well in Yukon. But now Yukon is beggining to perk interest in the mining industry because of things like highly developed road systems and new government programs spurring interest in the subject.
Where can I find them?
During the Klondike Gold Rush, Dawson City was the heart of the rush. Much of the gold was found there. 
Yukon Silver Trail once was filled with mining district. The trail begins at Whitehorse, and then you eventually get the to town of Mayo. The Mayo Landing was established in the 1900's as the port for silver and lead shipments from the Keno District. At the end of the Silver Trail, you will come to Keno City.