Medium-sized butterfly, two very large eyespots on hind wing as shown. Taking nectar from thistles in riparian corridor through mixed conifer forest with Gambel's Oak, chokecherry, and other shrubs in understory.
Nectaring at Frostweed.
Along the central trail, wouldn't let me get a good photo
The American Painted Lady or American Lady (Vanessa virginiensis) is a butterfly found throughout North America.