I don't know if this is the one my dad used to hear on Alaska Airlines, but I was able to find a CD-ROM, kinda pricey at 49.95us, which has the following:

The Voice of Robert W. Service The era was encapsulated and immortalized by the poet, Robert W. Service. Klondike Gold contains a rare recording of the acknowledged bard of the Yukon reciting his most famous work, "The Cremation of Sam McGee", as well as an equally rare radio interview...

at the Dawson museum site. I will keep looking for a less expensive tape of this; I would LOVE to hear him reading his own poems! kat