The owl was disturbed from a grove of small hackberries, from which it darted into a short gully. I was able to quietly follow and get a few photos from above.
Its small size and slenderness makes me think Long-eared rather than Great-horned. It seems to feature the belly pattern described for Long-ears on this site: https://theiwrc.org/raptorID/comparisons/ghow_leow.html