Update:
I found several of these at Cedar Bog again this year. The last one might be Hexatoma brevicornis, so if you have expertise, please D.
https://www.inaturalist.org/observations/172420801
https://www.inaturalist.org/observations/172420799
https://www.inaturalist.org/observations/172420798
https://www.inaturalist.org/observations/175243975

Note: I have photographed this Hexatomini at Cedar Bog in Champaign County, Ohio for at least 17 years. Always in the same area.
I've added two other observations; one from back in 2004.
Links to those observations:
https://www.inaturalist.org/observations/88273567
https://www.inaturalist.org/observations/84762884
Here's an observation this year (2022) with better pics of wing venation. Same location.
https://www.inaturalist.org/observations/124010854

A cool thing I witnessed thanks to radio-telemetry. This was one of our largest rattlers (a male) and he was nearly back at his den at this point in the year. It took him 45-50 min. to get his meal down.