I keyed this to family Scathophagidae in Borror et al(1) and Cole(2), and to genus Scathophaga in Cole(2). So I was happy to see it looked at home with many of the BugGuide images under that heading. Nevertheless, I'm still a novice and would appreciate confirmation or correction.

Photographed within a clump of Rabbitbrush (Chrysothamnus nauseosus) which was in raging bloom, and was thus a fall oasis of insect activity in this relatively desiccated desert canyon.

The last three images illustrate a curious leg behavior.