Supai Canyon, AZ bug
We came across a number of these bugs in Supai Canyon, Arizona. They came out every night at dusk, and would stay fluttering on the same tree branch (or hidden inside of our drying pants) all night, then fly away sometime in the morning. They were about five inches long, and among the most terrifying insects I’ve ever seen. We only saw them in a particular spot near the river. They’re similar to some of the antilions on your site, but I couldn’t find it specifically. Thought you might like the photos, anyway (got one in flight!)
Despite his frightening appearance, this male Dobsonfly is harmless.