WaltF clued us in to this one. OU had a rope tow that was authorized and built in 1962, shows up on DTE aerial photos from 1967, and is mentioned in the school newspaper in 1976. I have moved Walt’s post to appear below because he includes links to each of his sources.
What is interesting to me is that my wife attended OU in the mid-’60s and again in the early ’70s. She says the tow was not operating during the winters of ’66 and ’67, but that it was in the early ’70s. She remembers “traying” on the hill next to the IM building in the ’60s and says there was no tow for skiers. Perhaps there was a break in operations, or perhaps she just doesn’t remember. After all, she neglected to tell me about this tow and I had to find out from Walt.