That would likely have been a Great Horned. Those rascals are not the biggest North American owl, but they are likely the strongest. Small cats don't have much of a chance. Even a medium or largish cat could be hurt or killed. OTOH, taking on a large cat could be a mistake for the owl.
The most recent cat of ours somehow learned about Bald Eagles while on our boat on the coast. I would have liked to see how she managed that. It must have been an interesting miss by the eagle. That cat used up the last of her lives later, likely in an encounter with a lynx. There were a few around that year because we were at the peak of the hare cycle. At times a person could see several hares at once out in the yard, and lynx tracks were frequently in the yard too.
The various cats in our lives have now been replaced by a certain dog.
