Originally I thought the prey animal was a cottontail rabbit, but I just couldn't see well
enough in the fading light, then when I got home and was able to zoom in on the computer I
could see it was some form of large rodent.

Long dagger like front claws, short stubby back toes, incisor teeth, and short to no ears...
and the rest of the animal is covered too much by the owl. Kinda like a gopher on steroids.

Too small for a marmot, maybe a Muskrat? Don't think we have Nutria around here, heck I
don't know. Anyone else have any ideas??

Next picture shows a cropped version of the rodents head and claws.

Closest I can figure is this is a Muskrat!